Content: Remove variation selector code from arrow emoji.

The variation selector code is causing Safari to render these arrows as [?]. Rather than chase that down, we can remove the variation selector code, in favor of adding the `wp-exclude-emoji` class to the arrow wrapper span. This fixes the arrows in Safari, while still preventing the emoji replacement.

See WordPress/wporg-mu-plugins#578

source/wp-content/themes/wporg-parent-2021/functions.php

@@ -18,8 +18,6 @@
 add_filter( 'author_link', __NAMESPACE__ . '\use_wporg_profile_for_author_link', 10, 3 );
 add_filter( 'render_block_core/pattern', __NAMESPACE__ . '\add_aria_hidden_to_arrows', 19 );
 add_filter( 'the_content', __NAMESPACE__ . '\add_aria_hidden_to_arrows', 19 );
-add_filter( 'render_block_core/pattern', __NAMESPACE__ . '\prevent_arrow_emoji', 20 );
-add_filter( 'the_content', __NAMESPACE__ . '\prevent_arrow_emoji', 20 );
 add_filter( 'wp_theme_json_data_theme', __NAMESPACE__ . '\merge_parent_child_theme_json' );
 
 // Enable embeds in patterns.
@@ -108,21 +106,7 @@ function use_wporg_profile_for_author_link( $link, $author_id, $author_nicename
  * @return string The updated content.
  */
 function add_aria_hidden_to_arrows( $content ) {
-	return preg_replace( '/([←↑→↓↔↕↖↗↘↙])/u', '<span aria-hidden="true">\1</span>', $content );
-}
-
-/**
- * Add the variation-selector unicode character to any arrow. This will force
- * the twemoji script to skip these characters, leaving them as text.
- *
- * Can be removed once the `wp-exclude-emoji` issue is fixed.
- * See https://core.trac.wordpress.org/ticket/52219.
- *
- * @param string $content Content of the current post.
- * @return string The updated content.
- */
-function prevent_arrow_emoji( $content ) {
-	return preg_replace( '/([←↑→↓↔↕↖↗↘↙])/u', '\1&#65038;', $content );
+	return preg_replace( '/([←↑→↓↔↕↖↗↘↙])/u', '<span aria-hidden="true" class="wp-exclude-emoji">\1</span>', $content );
 }
 
 /**