Tests: Improve test cleanup for block supports

Let's unregister the block in the tear_down method. The block will be unregistered even if the test fails.

Props ramonopoly, antonvlasenko.
See #55505.
Follow-up [53085], [53076].


Built from https://develop.svn.wordpress.org/trunk@53153


git-svn-id: https://core.svn.wordpress.org/trunk@52742 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-53152';
+$wp_version = '6.0-alpha-53153';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.