Favorites and My Patterns grid patterns: two block comments close the wrong block #791

Two pattern files in the 2024 theme have a block comment that does not match the block it is meant to close.

1. patterns/_grid-mine.php, line 63: the Edit wp:button block is closed with <!-- /wp:paragraph -->. I mentioned this one in Show a status-aware empty state on My Patterns #758.
2. patterns/_grid-favorites.php, line 77: the message group inside wp:query-no-results ends with <!-- wp:group /-->. That is a new, empty, self-closing group block, not a closer, so the message group stays open.

I checked both with parse_blocks() and do_blocks() on WordPress 7.1.3.

The first one has no effect today. The block tree and the rendered HTML are the same as with <!-- /wp:button -->.

The second one shifts the blocks that follow. The spacer and the suggestions group become inner blocks of the message group, <!-- /wp:query-no-results --> closes the message group, and <!-- /wp:query --> closes wp:query-no-results. So the closing </div> of the outer query block (line 107) ends up inside wp:query-no-results. When the user has favorites, that block renders nothing, and the rendered pattern has one <div> that is never closed.

An HTML5 parser repairs this. With PHP 8.5's Dom\HTMLDocument, the DOM of the full page-favorites.html template was the same with and without the fix, ignoring whitespace. So I do not expect a visible change. The served HTML is still unbalanced, and the block tree is not what the file intends.

Expected: each block comment closes the block it opened.