Editor Script: Add back compat with WP 6.5

[obenland]

Testing the new blocks in WordPress 6.5 I noticed errors for the EditorPlugin in the Editor. It looks like the Core-bundled version of the @wordpress/editor package in WP 6.5 doesn't yet contain the PluginDocumentSettingPanel component.
I added a dependency on @wordpress/edit-post, which is where it lived back then, as a fallback.

Proposed changes:

• Adds @wordpress/edit-post to npm dev dependencies.
• Adds fallback for PluginDocumentSettingPanel in WP 6.5.

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• On WordPress 6.5, open the Block Editor and make sure there is no red banner with an error notice at the top of the screen.

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Fixes a bug in WordPress 6.5 where the plugin settings in the Editor would fail to render, due to a backwards compatibility break.