Use real flutter root for finding pub in command integration test (#64021)

packages/flutter_tools/test/commands.shard/hermetic/analyze_continuously_test.dart

@@ -6,6 +6,7 @@ import 'dart:async';
 
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/common.dart';
+import 'package:flutter_tools/src/cache.dart';
 import 'package:mockito/mockito.dart';
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
@@ -17,13 +18,16 @@ import 'package:flutter_tools/src/commands/analyze.dart';
 import 'package:flutter_tools/src/dart/analysis.dart';
 import 'package:flutter_tools/src/dart/pub.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
-import 'package:flutter_tools/src/runner/flutter_command_runner.dart';
 import 'package:process/process.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
 
 void main() {
+  setUpAll(() {
+    Cache.flutterRoot = getFlutterRoot();
+  });
+
   AnalysisServer server;
   Directory tempDir;
   FileSystem fileSystem;
@@ -33,13 +37,11 @@ void main() {
   Logger logger;
 
   setUp(() {
-    platform = const LocalPlatform();
     fileSystem = LocalFileSystem.instance;
     platform = const LocalPlatform();
     processManager = const LocalProcessManager();
     terminal = AnsiTerminal(platform: platform, stdio: Stdio());
     logger = BufferLogger(outputPreferences: OutputPreferences.test(), terminal: terminal);
-    FlutterCommandRunner.initFlutterRoot();
     tempDir = fileSystem.systemTempDirectory.createTempSync('flutter_analysis_test.');
   });