Administration: Introduce `new_admin_email_subject` filter.

This changeset introduces the `new_admin_email_subject` hook which allow developers to filter the subject of the email sent when a change of site admin email address is attempted.

Props MadtownLems, johnbillion, alexanderkoledov, shooper, Marc_J, nikmeyer, xlthlx, devmuhib, nuhel, audrasjb.
Fixes #59250.




Built from https://develop.svn.wordpress.org/trunk@57283


git-svn-id: http://core.svn.wordpress.org/trunk@56789 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/misc.php

@@ -1531,16 +1531,23 @@ All at ###SITENAME###
 		$site_title = parse_url( home_url(), PHP_URL_HOST );
 	}
 
-	wp_mail(
-		$value,
-		sprintf(
-			/* translators: New admin email address notification email subject. %s: Site title. */
-			__( '[%s] New Admin Email Address' ),
-			$site_title
-		),
-		$content
+	$subject = sprintf(
+		/* translators: New admin email address notification email subject. %s: Site title. */
+		__( '[%s] New Admin Email Address' ),
+		$site_title
 	);
 
+	/**
+	 * Filters the subject of the email sent when a change of site admin email address is attempted.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $subject Subject of the email.
+	 */
+	$subject = apply_filters( 'new_admin_email_subject', $subject );
+
+	wp_mail( $value, $subject, $content );
+
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-alpha-57282';
+$wp_version = '6.5-alpha-57283';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.