only in patch2:
unchanged:
--- a/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php
+++ b/core/modules/ckeditor/src/Tests/CKEditorAdminTest.php
@@ -115,6 +115,9 @@ function testExistingFormat() {
     $expected_buttons_value = json_encode($expected_default_settings['toolbar']['rows']);
     $this->assertFieldByName('editor[settings][toolbar][button_groups]', $expected_buttons_value);
 
+    $require_alt_text = $this->xpath('//input[@type="checkbox" and @name="editor[settings][plugins][drupalimage][image_upload][require_alt_text]" and not(@checked)]');
+    $this->assertTrue(count($require_alt_text) === 1, 'Require alt text checkbox was found and was not checked.');
+
     // Ensure the styles textarea exists and is initialized empty.
     $styles_textarea = $this->xpath('//textarea[@name="editor[settings][plugins][stylescombo][styles]"]');
     $this->assertFieldByXPath('//textarea[@name="editor[settings][plugins][stylescombo][styles]"]', '', 'The styles textarea exists and is empty.');