Tests: Remove obsolete page builder skip tests from cross-origin isolation.

Remove tests for the page builder action check that was moved to a
separate PR (WordPress#11170).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: adamsilverstein

tests/phpunit/tests/media/wpSetUpCrossOriginIsolation.php

@@ -8,20 +8,11 @@
  */
 class Tests_Media_wpSetUpCrossOriginIsolation extends WP_UnitTestCase {
 
-	/**
-	 * Original $_GET values.
-	 *
-	 * @var array
-	 */
-	private $original_get;
-
 	public function set_up() {
 		parent::set_up();
-		$this->original_get = $_GET;
 	}
 
 	public function tear_down() {
-		$_GET = $this->original_get;
 		remove_all_filters( 'wp_client_side_media_processing_enabled' );
 		parent::tear_down();
 	}
@@ -45,27 +36,4 @@ public function test_returns_early_when_no_screen() {
 
 		$this->assertSame( $level_before, $level_after );
 	}
-
-	public function test_skips_for_third_party_editor_action() {
-		$_GET['action'] = 'third_party_editor';
-
-		$level_before = ob_get_level();
-		wp_set_up_cross_origin_isolation();
-		$level_after = ob_get_level();
-
-		$this->assertSame( $level_before, $level_after, 'Should skip when action is not "edit".' );
-	}
-
-	public function test_does_not_skip_for_edit_action() {
-		$_GET['action'] = 'edit';
-
-		// Still won't start the buffer because no screen is set,
-		// but confirms the action check doesn't block 'edit'.
-		$level_before = ob_get_level();
-		wp_set_up_cross_origin_isolation();
-		$level_after = ob_get_level();
-
-		// Returns early at the screen check, not the action check.
-		$this->assertSame( $level_before, $level_after );
-	}
 }