Revert "PLANET-7183 Fix search password protected content"

This reverts commit afdd03d.

src/Search.php

@@ -251,7 +251,7 @@ function ($args) {
             1
         );
         add_filter(
-            'pre_get_posts',
+            'ep_post_query_db_args',
             [ self::class, 'hide_password_protected_content' ],
             10,
             1
@@ -1091,14 +1091,14 @@ public static function exclude_page_for_posts(WP_Query $query): WP_Query
     /**
      * Exclude password protected content from ElasticPress sync.
      *
-     * @param WP_Query $query The Query ElasticPress will use to fetch the ids of posts.
+     * @param mixed[] $args The args ElasticPress will use to fetch the ids of posts that will be synced.
      *
-     * @return WP_Query The query with exclusion of password protected content.
+     * @return mixed The args with exclusion of password protected content.
      */
-    public static function hide_password_protected_content(WP_Query $query): WP_QUERY
+    public static function hide_password_protected_content(array $args)
     {
-        $query->set('has_password', false);
+        $args['has_password'] = false;
 
-        return $query;
+        return $args;
     }
 }