Revert "validate engine hash (#55057)" (#55220)

This reverts commit 98651c02.

dev/bots/run_command.dart

@@ -80,7 +80,7 @@ Future<void> runCommand(String executable, List<String> arguments, {
   );
 
   final String commandDescription = '${path.relative(executable, from: workingDirectory)} ${arguments.join(' ')}';
-  final String relativeWorkingDir = path.relative(workingDirectory ?? Directory.current.path);
+  final String relativeWorkingDir = path.relative(workingDirectory);
   if (skip) {
     printProgress('SKIPPING', relativeWorkingDir, commandDescription);
     return;

dev/bots/test.dart

@@ -26,26 +26,12 @@ typedef ShardRunner = Future<void> Function();
 /// appropriate error message.
 typedef OutputChecker = String Function(CapturedOutput);
 
-final String exe = Platform.isWindows ? '.exe' : '';
-final String bat = Platform.isWindows ? '.bat' : '';
 final String flutterRoot = path.dirname(path.dirname(path.dirname(path.fromUri(Platform.script))));
-final String flutter = path.join(flutterRoot, 'bin', 'flutter$bat');
-final String dart = path.join(flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', 'dart$exe');
-final String pub = path.join(flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', 'pub$bat');
+final String flutter = path.join(flutterRoot, 'bin', Platform.isWindows ? 'flutter.bat' : 'flutter');
+final String dart = path.join(flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', Platform.isWindows ? 'dart.exe' : 'dart');
+final String pub = path.join(flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', Platform.isWindows ? 'pub.bat' : 'pub');
 final String pubCache = path.join(flutterRoot, '.pub-cache');
 final String toolRoot = path.join(flutterRoot, 'packages', 'flutter_tools');
-final String engineVersionFile = path.join(flutterRoot, 'bin', 'internal', 'engine.version');
-
-String get platformFolderName {
-  if (Platform.isWindows)
-    return 'windows-x64';
-  if (Platform.isMacOS)
-    return 'darwin-x64';
-  if (Platform.isLinux)
-    return 'linux-x64';
-  throw UnsupportedError('The platform ${Platform.operatingSystem} is not supported by this script.');
-}
-final String flutterTester = path.join(flutterRoot, 'bin', 'cache', 'artifacts', 'engine', platformFolderName, 'flutter_tester$exe');
 
 /// The arguments to pass to `flutter test` (typically the local engine
 /// configuration) -- prefilled with the arguments passed to test.dart.
@@ -132,18 +118,6 @@ Future<void> main(List<String> args) async {
 
 Future<void> _runSmokeTests() async {
   print('${green}Running smoketests...$reset');
-  // Verify the Flutter Engine is the revision we asked for.
-  final String expectedVersion = File(engineVersionFile).readAsStringSync().trim();
-  final CapturedOutput flutterTesterOutput = CapturedOutput();
-  await runCommand(flutterTester, <String>['--help'], output: flutterTesterOutput, outputMode: OutputMode.capture);
-  final String actualVersion = flutterTesterOutput.stderr.split('\n').firstWhere((final String line) {
-    return line.startsWith('Flutter Engine Version:');
-  });
-  if (!actualVersion.contains(expectedVersion)) {
-    print('${red}Expected "Flutter Engine Version: $expectedVersion", '
-          'but found "$actualVersion".');
-    exit(1);
-  }
   // Verify that the tests actually return failure on failure and success on
   // success.
   final String automatedTests = path.join(flutterRoot, 'dev', 'automated_tests');
@@ -1178,6 +1152,7 @@ int get prNumber {
 }
 
 Future<String> _getAuthors() async {
+  final String exe = Platform.isWindows ? '.exe' : '';
   final String author = await runAndGetStdout(
     'git$exe', <String>['-c', 'log.showSignature=false', 'log', gitHash, '--pretty="%an <%ae>"'],
     workingDirectory: flutterRoot,