chore: deprecate thisArg signatures (#6361)

* chore: deprecate thisArg

* chore: deprecate source parameters

Closes #6143

* Revert "chore: deprecate source parameters"

This reverts commit 8bb2f84.
Closes #6143.

* chore: update api_guardian

api_guard/dist/types/operators/index.d.ts

@@ -76,7 +76,8 @@ export declare function endWith<T>(scheduler: SchedulerLike): MonoTypeOperatorFu
 export declare function endWith<T, A extends unknown[] = T[]>(...valuesAndScheduler: [...A, SchedulerLike]): OperatorFunction<T, T | ValueFromArray<A>>;
 export declare function endWith<T, A extends unknown[] = T[]>(...values: A): OperatorFunction<T, T | ValueFromArray<A>>;
 
-export declare function every<T>(predicate: BooleanConstructor, thisArg?: any): OperatorFunction<T, Exclude<T, Falsy> extends never ? false : boolean>;
+export declare function every<T>(predicate: BooleanConstructor): OperatorFunction<T, Exclude<T, Falsy> extends never ? false : boolean>;
+export declare function every<T>(predicate: BooleanConstructor, thisArg: any): OperatorFunction<T, Exclude<T, Falsy> extends never ? false : boolean>;
 export declare function every<T, A>(predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean, thisArg: A): OperatorFunction<T, boolean>;
 export declare function every<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, boolean>;
 
@@ -105,7 +106,8 @@ export declare function find<T, S extends T>(predicate: (value: T, index: number
 export declare function find<T, A>(predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean, thisArg: A): OperatorFunction<T, T | undefined>;
 export declare function find<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, T | undefined>;
 
-export declare function findIndex<T>(predicate: BooleanConstructor, thisArg?: any): OperatorFunction<T, T extends Falsy ? -1 : number>;
+export declare function findIndex<T>(predicate: BooleanConstructor): OperatorFunction<T, T extends Falsy ? -1 : number>;
+export declare function findIndex<T>(predicate: BooleanConstructor, thisArg: any): OperatorFunction<T, T extends Falsy ? -1 : number>;
 export declare function findIndex<T, A>(predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean, thisArg: A): OperatorFunction<T, number>;
 export declare function findIndex<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, number>;
 

src/internal/observable/partition.ts

@@ -4,6 +4,7 @@ import { ObservableInput } from '../types';
 import { Observable } from '../Observable';
 import { innerFrom } from './from';
 
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function partition<T, U extends T, A>(
   source: ObservableInput<T>,
   predicate: (this: A, value: T, index: number) => value is U,
@@ -14,6 +15,7 @@ export function partition<T, U extends T>(
   predicate: (value: T, index: number) => value is U
 ): [Observable<U>, Observable<Exclude<T, U>>];
 
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function partition<T, A>(
   source: ObservableInput<T>,
   predicate: (this: A, value: T, index: number) => boolean,

src/internal/operators/every.ts

@@ -3,10 +3,13 @@ import { Falsy, OperatorFunction } from '../types';
 import { operate } from '../util/lift';
 import { OperatorSubscriber } from './OperatorSubscriber';
 
+export function every<T>(predicate: BooleanConstructor): OperatorFunction<T, Exclude<T, Falsy> extends never ? false : boolean>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function every<T>(
   predicate: BooleanConstructor,
-  thisArg?: any
+  thisArg: any
 ): OperatorFunction<T, Exclude<T, Falsy> extends never ? false : boolean>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function every<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A

src/internal/operators/filter.ts

@@ -2,9 +2,11 @@ import { OperatorFunction, MonoTypeOperatorFunction, TruthyTypesOf } from '../ty
 import { operate } from '../util/lift';
 import { OperatorSubscriber } from './OperatorSubscriber';
 
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function filter<T, S extends T, A>(predicate: (this: A, value: T, index: number) => value is S, thisArg: A): OperatorFunction<T, S>;
 export function filter<T, S extends T>(predicate: (value: T, index: number) => value is S): OperatorFunction<T, S>;
 export function filter<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function filter<T, A>(predicate: (this: A, value: T, index: number) => boolean, thisArg: A): MonoTypeOperatorFunction<T>;
 export function filter<T>(predicate: (value: T, index: number) => boolean): MonoTypeOperatorFunction<T>;
 

src/internal/operators/find.ts

@@ -5,13 +5,15 @@ import { operate } from '../util/lift';
 import { OperatorSubscriber } from './OperatorSubscriber';
 
 export function find<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function find<T, S extends T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => value is S,
   thisArg: A
 ): OperatorFunction<T, S | undefined>;
 export function find<T, S extends T>(
   predicate: (value: T, index: number, source: Observable<T>) => value is S
 ): OperatorFunction<T, S | undefined>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function find<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A

src/internal/operators/findIndex.ts

@@ -3,7 +3,10 @@ import { Falsy, OperatorFunction } from '../types';
 import { operate } from '../util/lift';
 import { createFind } from './find';
 
-export function findIndex<T>(predicate: BooleanConstructor, thisArg?: any): OperatorFunction<T, T extends Falsy ? -1 : number>;
+export function findIndex<T>(predicate: BooleanConstructor): OperatorFunction<T, T extends Falsy ? -1 : number>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
+export function findIndex<T>(predicate: BooleanConstructor, thisArg: any): OperatorFunction<T, T extends Falsy ? -1 : number>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function findIndex<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A

src/internal/operators/map.ts

@@ -3,6 +3,7 @@ import { operate } from '../util/lift';
 import { OperatorSubscriber } from './OperatorSubscriber';
 
 export function map<T, R>(project: (value: T, index: number) => R): OperatorFunction<T, R>;
+/** @deprecated Use a closure instead of a `thisArg`. Signatures accepting a `thisArg` will be removed in v8. */
 export function map<T, R, A>(project: (this: A, value: T, index: number) => R, thisArg: A): OperatorFunction<T, R>;
 
 /**