Date/Time: Correct the time format in `get_feed_build_date()` to use 24-hour format.

Follow-up to [46756].

See #48675.
Built from https://develop.svn.wordpress.org/trunk@46757


git-svn-id: http://core.svn.wordpress.org/trunk@46557 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/feed.php

@@ -683,7 +683,7 @@ function get_feed_build_date( $format ) {
 
 	// Determine the maximum modified time.
 	$datetime = date_create_immutable_from_format(
-		'Y-m-d h:i:s',
+		'Y-m-d H:i:s',
 		max( $modified_times ),
 		new DateTimeZone( 'UTC' )
 	);

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.4-alpha-46756';
+$wp_version = '5.4-alpha-46757';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.