Fix: Restrict export pattern action to user patterns

[ntsekouras]

What?

According to this issue: #61787 the export pattern action is not meant to be for theme patterns. With a recent refactoring of that action this regressed and we ended up with showing this action in theme patterns, which also caused other issues of not exporting properly(#63217).

I think the solution is to add back the check about the wp_block (theme patterns have type===pattern). This makes it a bit confusing though with our API for registering actions, which right now is registerEntityAction( 'postType', 'wp_block', exportPattern );.

We should look into the type===pattern and where/why is needed..

Testing Instructions

1. Exporting/importing patterns should work properly in patterns list (there is an open issue for the post summary actions)
2. Export action should not be available for theme patterns

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: ntsekouras <ntsekouras@git.wordpress.org>
Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[ramonjd]

LGTM

I can export custom patterns but not theme patterns 👍🏻

[t-hamano]

LGTM!

Not a blocker, but I think it might be better to use PATTERN_TYPES.user instead of a hardcoded string.

However, it seems necessary to write @ts-ignore to avoid type errors in typescript file, like here:

gutenberg/packages/editor/src/dataviews/actions/delete-post.tsx

Lines 14 to 15 in 879cdc5

	// @ts-ignore
	import { privateApis as patternsPrivateApis } from '@wordpress/patterns';