Revert "chore: deprecate source parameters"

This reverts commit 8bb2f84.
Closes ReactiveX#6143.

src/internal/operators/every.ts

@@ -14,8 +14,6 @@ export function every<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A
 ): OperatorFunction<T, boolean>;
-export function every<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<T, boolean>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function every<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, boolean>;
 
 /**

src/internal/operators/find.ts

@@ -10,8 +10,6 @@ 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) => value is S): OperatorFunction<T, S | undefined>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function find<T, S extends T>(
   predicate: (value: T, index: number, source: Observable<T>) => value is S
 ): OperatorFunction<T, S | undefined>;
@@ -20,10 +18,7 @@ export function find<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A
 ): OperatorFunction<T, T | undefined>;
-export function find<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<T, T | undefined>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function find<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, T | undefined>;
-
 /**
  * Emits only the first value emitted by the source Observable that meets some
  * condition.

src/internal/operators/findIndex.ts

@@ -11,8 +11,6 @@ export function findIndex<T, A>(
   predicate: (this: A, value: T, index: number, source: Observable<T>) => boolean,
   thisArg: A
 ): OperatorFunction<T, number>;
-export function findIndex<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<T, number>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function findIndex<T>(predicate: (value: T, index: number, source: Observable<T>) => boolean): OperatorFunction<T, number>;
 
 /**

src/internal/operators/first.ts

@@ -10,20 +10,14 @@ import { identity } from '../util/identity';
 export function first<T, D = T>(predicate?: null, defaultValue?: D): OperatorFunction<T, T | D>;
 export function first<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
 export function first<T, D>(predicate: BooleanConstructor, defaultValue: D): OperatorFunction<T, TruthyTypesOf<T> | D>;
-export function first<T, S extends T>(predicate: (value: T, index: number) => value is S, defaultValue?: S): OperatorFunction<T, S>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function first<T, S extends T>(
   predicate: (value: T, index: number, source: Observable<T>) => value is S,
   defaultValue?: S
 ): OperatorFunction<T, S>;
-export function first<T, S extends T, D>(predicate: (value: T, index: number) => value is S, defaultValue: D): OperatorFunction<T, S | D>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function first<T, S extends T, D>(
   predicate: (value: T, index: number, source: Observable<T>) => value is S,
   defaultValue: D
 ): OperatorFunction<T, S | D>;
-export function first<T, D = T>(predicate: (value: T, index: number) => boolean, defaultValue?: D): OperatorFunction<T, T | D>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function first<T, D = T>(
   predicate: (value: T, index: number, source: Observable<T>) => boolean,
   defaultValue?: D

src/internal/operators/last.ts

@@ -10,14 +10,10 @@ import { identity } from '../util/identity';
 export function last<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
 export function last<T, D>(predicate: BooleanConstructor, defaultValue: D): OperatorFunction<T, TruthyTypesOf<T> | D>;
 export function last<T, D = T>(predicate?: null, defaultValue?: D): OperatorFunction<T, T | D>;
-export function last<T, S extends T>(predicate: (value: T, index: number) => value is S, defaultValue?: S): OperatorFunction<T, S>;
-export function last<T, D = T>(predicate: (value: T, index: number) => boolean, defaultValue?: D): OperatorFunction<T, T | D>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function last<T, S extends T>(
   predicate: (value: T, index: number, source: Observable<T>) => value is S,
   defaultValue?: S
 ): OperatorFunction<T, S>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function last<T, D = T>(
   predicate: (value: T, index: number, source: Observable<T>) => boolean,
   defaultValue?: D

src/internal/operators/single.ts

@@ -8,8 +8,6 @@ import { operate } from '../util/lift';
 import { OperatorSubscriber } from './OperatorSubscriber';
 
 export function single<T>(predicate: BooleanConstructor): OperatorFunction<T, TruthyTypesOf<T>>;
-export function single<T>(predicate?: (value: T, index: number) => boolean): MonoTypeOperatorFunction<T>;
-/** @deprecated Use a closure instead of a `source` parameter. Support for predicates taking a `source` parameter will be removed in v8. */
 export function single<T>(predicate?: (value: T, index: number, source: Observable<T>) => boolean): MonoTypeOperatorFunction<T>;
 
 /**