Revert FPS counter (#17485)

**UPDATE**: Response so far seems to be that this fixes the performance
issues on Intel MacBooks. So we're going to go ahead and merge it.

This reverts the FPS counter added in 11753914d (#16422) because in this
issue someone bisected recent performance regressions down to this
commit:

- https://github.com/zed-industries/zed/issues/16729

Another issue that's possibly related:

-
https://github.com/zed-industries/zed/issues/17305#issuecomment-2332316242

We're reverting this in a PR to create a bundle that people can try out.

Assets:

- Universal Binary:
https://github.com/zed-industries/zed/actions/runs/10735702994/artifacts/1900460781
- x86/Intel:
https://github.com/zed-industries/zed/actions/runs/10735702994/artifacts/1900461236
- Apple Silicon:
https://github.com/zed-industries/zed/actions/runs/10735702994/artifacts/1900460978


Release Notes:

- Removed the recently-added FPS counter since the changes it made to
the Metal renderer on macOS could lead to performance regressions on
Intel MacBooks.

Co-authored-by: Bennet <bennet@zed.dev>