Revert "Issue #3317520 by mstrelan, nod_, wim leers: [random test failure]...

Revert "Issue #3317520 by mstrelan, nod_, wim leers: [random test failure] Drupal\Tests\settings_tray\FunctionalJavascript\SettingsTrayBlockFormTest::testEditModeEnableDisable"

This reverts commit 853031b6.

core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayBlockFormTest.php

@@ -6,7 +6,6 @@
 
 use Drupal\settings_tray_test\Plugin\Block\SettingsTrayFormAnnotationIsClassBlock;
 use Drupal\settings_tray_test\Plugin\Block\SettingsTrayFormAnnotationNoneBlock;
-use Drupal\Tests\WaitTerminateTestTrait;
 use Drupal\user\Entity\Role;
 
 /**
@@ -16,8 +15,6 @@
  */
 class SettingsTrayBlockFormTest extends SettingsTrayTestBase {
 
-  use WaitTerminateTestTrait;
-
   /**
    * {@inheritdoc}
    */
@@ -47,7 +44,6 @@ protected function setUp(): void {
       'search content',
     ]);
     $this->drupalLogin($user);
-    $this->setWaitForTerminate();
   }
 
   /**
@@ -235,6 +231,7 @@ public function getBlockTests() {
    * Tests enabling and disabling Edit Mode.
    */
   public function testEditModeEnableDisable(): void {
+    $this->markTestSkipped("Skipped due to frequent random test failures. See https://www.drupal.org/project/drupal/issues/3317520");
     foreach (static::getTestThemes() as $theme) {
       $this->enableTheme($theme);
       $block = $this->placeBlock('system_powered_by_block');

core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php

@@ -49,10 +49,11 @@ protected function openBlockForm($block_selector, $contextual_link_container = '
     // When page first loads Edit Mode is not triggered until first contextual
     // link is added.
     $this->assertNotEmpty($this->assertSession()->waitForElementVisible('css', '.dialog-off-canvas-main-canvas.js-settings-tray-edit-mode'));
+    // @todo https://www.drupal.org/project/drupal/issues/3317520 Work why the
+    //   sleep is necessary in.
+    usleep(100000);
 
-    $block = $this->assertSession()->waitForElementVisible('css', $block_selector);
-    $this->assertNotEmpty($block);
-
+    $block = $this->getSession()->getPage()->find('css', $block_selector);
     $block->mouseOver();
     $block->click();
     $this->waitForOffCanvasToOpen();