PY-22379: New test runners: background removed

python/src/com/jetbrains/python/testing/universalTests/PyUniversalTestForm.form

@@ -6,7 +6,6 @@
       <xy x="20" y="20" width="500" height="400"/>
     </constraints>
     <properties>
-      <background color="-12632257"/>
       <enabled value="false"/>
     </properties>
     <border type="none"/>
@@ -69,7 +68,6 @@
           <grid row="2" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false"/>
         </constraints>
         <properties>
-          <background color="-12828863"/>
         </properties>
         <border type="none"/>
         <children/>