type: fix ignoreElements generic type

[caikan]

Description:
If ignoreElements follows tap immediately, the type of the tap parameter will be incorrectly inferred to be unknown.

import { ignoreElements, of, tap } from 'rxjs';

function test() {
  const data = { value: 1 }
  of(data).pipe(
    tap(data => console.log(data.value)),
    // ---------------------^~~~ ['data' is of type 'unknown'.ts(18046)]
    ignoreElements(),
  )
}

[kwonoj]

Isn't this exactly same as #7204 (comment) ?

[benlesh]

I think this was already done in another commit.

Thank you so much for the PR, though, @caikan!!