[NIFI-13756] clear banner error afterClosed() of EditParameterContext dialog (#9329)

This closes #9329

nifi-frontend/src/main/frontend/apps/nifi/src/app/pages/parameter-contexts/state/parameter-context-listing/parameter-context-listing.effects.ts

@@ -170,6 +170,10 @@ export class ParameterContextListingEffects {
                                 })
                             );
                         });
+
+                    dialogReference.afterClosed().subscribe(() => {
+                        this.store.dispatch(ErrorActions.clearBannerErrors());
+                    });
                 })
             ),
         { dispatch: false }