gpui: Throttle framerate to 30 for unfocused windows (#52970)

This should reduce energy consumption when having agents running in
background windows, as the spinner that is being animated won't refresh
at the display framerate anymore.

Release Notes:

- N/A or Added/Fixed/Improved ...
72eb842540Lukas Wirth committed on 4/9/2026, 11:28:43 AM· committed by GitHubparent50856c9
1 file changedLine totals unavailable