MenuItem: Add 40px size prop on Button

[mirka]

In preparation for #65751

What?

Adds __next40pxDefaultSize prop to the Button in MenuItem.

Testing Instructions

See the MenuItem stories in Storybook. The heights should now be 40px instead of 36px.

(These changes mostly won't be seen in the app until we update the styles for DropdownMenu, which is currently overriding the MenuItem styles 😅)

[github-actions]

Flaky tests detected in a310d09.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/11599831079
📝 Reported issues:

• [Flaky Test] should be able to create a new tag with ' on the name #38828 in /test/e2e/specs/editor/various/taxonomies.spec.js

[github-actions]

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Co-authored-by: mirka <[email protected]>
Co-authored-by: tyxla <[email protected]>

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[tyxla]

LGTM, works as expected 👍

Also confirming this is the case wherever I tested:

(These changes mostly won't be seen in the app until we update the styles for DropdownMenu, which is currently overriding the MenuItem styles 😅)

Can you name any instances where MenuItem isn't used in a DropdownMenu so we can test them and ensure they work well?

[mirka]

Can you name any instances where MenuItem isn't used in a DropdownMenu so we can test them and ensure they work well?

I'm finding that the non-DropdownMenu implementations mimic the DropdownMenu internals, so they use NavigableMenu. Searching for instances of NavigableMenu seem to surface the MenuItem instances in question.

For example this media replace dropdown:

Or the Video block Text tracks dropdown: