MC-843: Heading live edit should become unfocused on drag action

- Removed testing test group

Author: Hwashiang Yu

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

@@ -1585,7 +1585,6 @@
             <testCaseId value="MC-3540"/>
             <group value="pagebuilder"/>
             <group value="pagebuilder-heading"/>
-            <group value="m"/>
         </annotations>
         <before>
             <actionGroup ref="LoginAsAdmin" stepKey="loginAsAdmin"/>