Remove unused variable (#2461)

* Remove unused variable

Follow up to #2458

* Fix additional test failure

* Fix type

Author: bkonyi

dwds/test/instances/common/test_inspector.dart

@@ -382,7 +382,6 @@ Object? _getValue(InstanceRef instanceRef) {
 final _dartCoreLibrary = 'dart:core';
 final _dartInterceptorsLibrary = 'dart:_interceptors';
 final _dartJsHelperLibrary = 'dart:_js_helper';
-final _dartCollectionLibrary = 'dart:collection';
 final _dartRuntimeLibrary = 'dart:_runtime';
 
 final matchRecordClassName = 'Record';

dwds/test/instances/common/type_inspection_common.dart

@@ -247,11 +247,11 @@ void runTests({
       await onBreakPoint('printSimpleLocalRecord', (event) async {
         final frame = event.topFrame!.index!;
         final instanceRef = await getInstanceRef(frame, '<int>{}.runtimeType');
-        expect(instanceRef, matchTypeInstanceRef('_IdentityHashSet<int>'));
+        expect(instanceRef, matchTypeInstanceRef('IdentitySet<int>'));
 
         final instanceId = instanceRef.id!;
         final instance = await getObject(instanceId);
-        expect(instance, matchTypeInstance('_IdentityHashSet<int>'));
+        expect(instance, matchTypeInstance('IdentitySet<int>'));
 
         final classId = instanceRef.classRef!.id;
         expect(await getObject(classId), matchTypeClass);