language_models: Remove `language-models` feature flag (#29416)

This PR removes the `language-models` feature flag.

This feature is already generally available, so we no longer need the
feature flag.

Release Notes:

- N/A
9be7bf72a4Marshall Bowers committed on 4/25/2025, 2:18:48 PM· committed by GitHubparent357e38b
2 files changedLine totals unavailable