keymap_editor: Move OpenKeymapEditor action into zed_actions (#37928)

This lets us remove title_bar's dependency on keymap_editor, which in
turns improves dev build times by ~0.5s for me

Release Notes:

- N/A
c0b583c9efPiotr Osiewicz committed on 9/10/2025, 4:57:05 PM· committed by GitHubparent6441099
6 files changedLine totals unavailable