cursor_shape: removing setting doesn't restore the default (bar) value

[warpdesign]

Check for existing issues

• Completed

Describe the bug / provide steps to reproduce it

• open settings and change the cursor_shape, for eg add "cursor_shape": "block" and save
• delete the previously added line and save again

The cursor shape will still be block: it should be set to the default one: bar.

Environment

Zed: v0.154.0 (Zed Preview)
OS: macOS 14.5.0
Memory: 32 GiB
Architecture: aarch64

If applicable, add mockups / screenshots to help explain present your vision of the feature

In the following video, the cursor shape is at the start set to the default (bar) value. I then change it to block and save: it's being updated as expected. But then I delete the setting, save, and the shape is still set to block.

zed_cursor_shape.mov

If applicable, attach your Zed.log file to this issue.

Zed.log

[notpeter]

I believe this may be a regression related to:

• editor: Fix cursor_shape regression by not setting it to "bar" #17934

CC: @mrnugget