style(ui): remove hover backgrounds from icon actions

src/features/http-client/HttpClient.module.css

@@ -16,9 +16,6 @@
   border-radius: var(--radius-small);
   cursor: pointer;
 }
-.runMarker:hover {
-  background: var(--bg-hover);
-}
 
 /* Toolbar panel above `.http` files. */
 .toolbar {