Remove the wp-has-aspect-ratio class from block embeds

[pierlon]

Summary

As of Gutenberg 8.2, when the wp-has-aspect-ratio class is set on an embed block, it adds a large gap to the top of the embed. This breaks the visual parity of the AMP page when compared to its non-AMP counterpart. For example:

The wp-has-aspect-ratio class is not needed in the AMP context because the responsive layout of the embed will be handled natively. When the class is removed, visual parity is restored:

Fixes #4810

Related: #1683

Checklist

• My pull request is addressing an open issue (please create one otherwise).
• My code is tested and passes existing tests.
• My code follows the Engineering Guidelines (updates are often made to the guidelines, check it out periodically).

[westonruter]

I can see this change between 8.1 and 8.2:

It came from this PR: https://github.com/WordPress/gutenberg/pull/21599/files?diff=split&w=1

[westonruter]

So what was formerly:

.wp-embed-responsive .wp-block-embed.wp-embed-aspect-16-9 .wp-block-embed__wrapper::before {
    padding-top: 56.25%;
}

Is now:

.wp-embed-responsive .wp-embed-aspect-16-9 .wp-block-embed__wrapper:before {
    padding-top: 56.25%;
}

[westonruter]

Basically we want to prevent this new CSS rule from applying:

[westonruter]

And this is the result when the wp-has-aspect-ratio class is removed.

[westonruter]

As opposed to using preg_replace_callback() would it make more sense to use array_filter()? So perhaps this would be marginally better:

$classes = array_filter(
	$classes,
	static function ( $class ) use ( &$responsive_width, &$responsive_height ) {
		if ( preg_match( '/^wp-embed-aspect-(?P<width>\d+)-(?P<height>\d+)$/', $class, $matches ) ) {
			$responsive_width  = $matches['width'];
			$responsive_height = $matches['height'];
			return false;
		}
		return 'wp-has-aspect-ratio' !== $class;
	}
);

[westonruter]

For that matter, this could also be used instead of the array_diff() above as well. (Now updated the above.)

[pierlon]

Addressed in ae78190.

[westonruter]

I've confirmed that an embed looks properly in WP 5.4 both when Gutenberg 8.3 is active and when it is inactive.