Tests: Declare the `$post_id` property in `wp_comments_personal_data_exporter()` tests.

Use the same approach in `wp_comments_personal_data_eraser()` for consistency and to minimize the number of fixtures created in each individual test.

Follow-up to [55319], [55321].

Props hellofromTonya.
See #56793.
Built from https://develop.svn.wordpress.org/trunk@55322


git-svn-id: http://core.svn.wordpress.org/trunk@54855 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.2-beta1-55321';
+$wp_version = '6.2-beta1-55322';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.