Build/Test Tools: Don't trigger a skipped test when the built version of `wp-embed.min.js` isn't present.

The grunt command assertion prior to the check for the existence of the file is enough to safeguard this test.

See #34698, #40533


git-svn-id: https://develop.svn.wordpress.org/trunk@40526 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/oembed/template.php

@@ -303,7 +303,7 @@ class Tests_Embed_Template extends WP_UnitTestCase {
 
 		$file = dirname( ABSPATH ) . '/build/' . WPINC . '/js/wp-embed.min.js';
 		if ( ! file_exists( $file ) ) {
-			$this->markTestSkipped( "This test is for the compiled wp-embed.min.js file." );
+			return;
 		}
 		$this->assertNotContains( '&', file_get_contents( $file ) );
 	}