Bug 1577834 - Remove now-useless promise array in ensureCSSErrorReportingEnabled. r=nchevobbe

Now that we no longer do anything when they all resolve, this can go away.

Differential Revision: https://phabricator.services.mozilla.com/D44222

--HG--
extra : moz-landing-system : lando

devtools/server/actors/targets/browsing-context.js

@@ -1133,17 +1133,14 @@ const browsingContextTargetPrototype = {
         docShell.document,
         /* documentOnly = */ true
       );
-      const promises = [];
       for (const sheet of sheets) {
         if (InspectorUtils.hasRulesModifiedByCSSOM(sheet)) {
           continue;
         }
         // Reparse the sheet so that we see the existing errors.
-        promises.push(
         getSheetText(sheet, this._consoleActor).then(text => {
           InspectorUtils.parseStyleSheet(sheet, text, /* aUpdate = */ false);
-          })
-        );
+        });
       }
     }