Tests: Reset timezone-related options if the tests change them.

The `options` table is not explicitly reset after each test or test class, so if an option is changed during a test, it should be reset to the default value ''after'' the test.

This commit does so for those tests which did not have such resetting in place yet, while one or more tests in the class ''do'' change the value of the `timezone_string` option.

Note: The test suite executes a `ROLLBACK` query after each test, which should reset the `options` table in theory, however that appears to not always be enough, as some timezone-related tests can fail in a complete test suite run, while not failing when run in isolation. This commit aims to improve stability of the tests.

Follow-up to [45857] / #45821.

Props jrf, costdev.
See #56468.
Built from https://develop.svn.wordpress.org/trunk@54207


git-svn-id: http://core.svn.wordpress.org/trunk@53766 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-54206';
+$wp_version = '6.1-alpha-54207';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.