Docs: Correct the type of the $return parameter in embed_handler_html filter.

The value cannot be `false` at this point, as the filter is only applied to non-empty embed HTML.

Follow-up to [25726], [46661].

Reviewed by SergeyBiryukov, audrasjb.
Merges [60149] to 6.8 branch.
Props apermo, jasonsa19.
Fixes #63248.



git-svn-id: https://develop.svn.wordpress.org/branches/6.8@60157 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-embed.php

@@ -163,9 +163,9 @@ class WP_Embed {
 						 *
 						 * @see WP_Embed::shortcode()
 						 *
-						 * @param string|false $return The HTML result of the shortcode, or false on failure.
-						 * @param string       $url    The embed URL.
-						 * @param array        $attr   An array of shortcode attributes.
+						 * @param string $return The HTML result of the shortcode.
+						 * @param string $url    The embed URL.
+						 * @param array  $attr   An array of shortcode attributes.
 						 */
 						return apply_filters( 'embed_handler_html', $return, $url, $attr );
 					}