Remove unused action

This is a remnant of another approach I tried when rerouting
/optimize when the filter excluded all summaries.

ui/app/controllers/optimize.js

@@ -182,15 +182,6 @@ export default class OptimizeController extends Controller {
     this.ensureActiveSummaryIsNotExcluded();
   }
 
-  @action
-  transitionToFirstSummary() {
-    const firstFilteredSummary = this.filteredSummaries.objectAt(0);
-
-    if (firstFilteredSummary) {
-      this.transitionToSummary(firstFilteredSummary);
-    }
-  }
-
   @action
   ensureActiveSummaryIsNotExcluded() {
     scheduleOnce('actions', () => {