MC-3357: Delete divider

- Updated delete divider test testcase id

Author: Michael Yu

app/code/Magento/PageBuilder/Test/Mftf/Test/AdminPageBuilderDividerTest.xml

@@ -870,7 +870,7 @@
         <actionGroup ref="switchToPageBuilderStage" stepKey="switchToPageBuilderStage"/>
         <!-- Delete Divider -->
         <comment userInput="Delete Divider" stepKey="commentDeleteDivider"/>
-        <actionGroup ref="z" stepKey="removeContentTypeFromStage">
+        <actionGroup ref="removeContentTypeFromStage" stepKey="removeContentTypeFromStage">
             <argument name="contentType" value="PageBuilderDividerContentType"/>
         </actionGroup>
         <!-- Validate Stage -->