Remove the redundant async keywoard

ee/spec/frontend/vulnerabilities/vulnerability_state_dropdown_spec.js

@@ -140,7 +140,7 @@ describe('Vulnerability state dropdown component', () => {
         });
     });
 
-    it('when the parent component changes the state, the dropdown will update its selected and initial item', async () => {
+    it('when the parent component changes the state, the dropdown will update its selected and initial item', () => {
       const [stateString, stateObject] = vulnerabilityStateEntries[1];
 
       wrapper.setProps({ initialState: stateString }); // Change the state.