Remove experimental microphone gain normalization option (#58677)

Release Notes:

- Removed the `experimental.auto_microphone_volume` setting (since
#58036 microphone volumes are now normalized by default)
b762980b3eConrad Irwin committed on 6/5/2026, 4:49:42 PM· committed by GitHubparent0ee1a80
6 files changedLine totals unavailable