Tests: Fix tests introduced in [55612].

In [55612] a change was added that made two unit tests fail. Fix these test by forcing `get_merged_data` method to run.  

Props spacedmonkey, mukesh27.
See #57814.
Built from https://develop.svn.wordpress.org/trunk@55613


git-svn-id: http://core.svn.wordpress.org/trunk@55125 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.3-alpha-55612';
+$wp_version = '6.3-alpha-55613';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.