Unskip test

Closes #3351516

core/modules/media/tests/src/FunctionalJavascript/MediaSourceFileTest.php

@@ -23,8 +23,6 @@ class MediaSourceFileTest extends MediaSourceTestBase {
    * Tests the file media source.
    */
   public function testMediaFileSource(): void {
-    // Skipped due to frequent random test failures.
-    $this->markTestSkipped();
     $media_type_id = 'test_media_file_type';
     $source_field_id = 'field_media_file';
     $provided_fields = [