Zoom out all panes when opening a dock (#2554)

Fixes
https://linear.app/zed-industries/issue/Z-2051/center-zoom-isnt-unset-when-opening-project-panel

Release Notes:

- Fixed a bug where opening the project panel did not reset the zoom
state of a pane.
0bd9d5b1faMax Brunsfeld committed on 6/1/2023, 10:26:46 PM· committed by GitHubparentsa55eafa585d13d
1 file changedLine totals unavailable