Disable tests that fail on non-master branches from running on those branches (#45455)

https://github.com/flutter/flutter/issues/45453
diff --git a/dev/bots/test.dart b/dev/bots/test.dart
index e26c955..ee77920 100644
--- a/dev/bots/test.dart
+++ b/dev/bots/test.dart
@@ -291,12 +291,20 @@
       await _flutterBuildIpa(examplePath);
     }
   }
-  // Web compilation tests.
-  await _flutterBuildDart2js(path.join('dev', 'integration_tests', 'web'), path.join('lib', 'main.dart'));
-  // Should not fail to compile with dart:io.
-  await _flutterBuildDart2js(path.join('dev', 'integration_tests', 'web_compile_tests'),
-    path.join('lib', 'dart_io_import.dart'),
-  );
+
+  final String branch = Platform.environment['CIRRUS_BRANCH'];
+  if (branch != 'beta' && branch != 'stable') {
+    // Web compilation tests.
+    await _flutterBuildDart2js(
+      path.join('dev', 'integration_tests', 'web'),
+      path.join('lib', 'main.dart'),
+    );
+    // Should not fail to compile with dart:io.
+    await _flutterBuildDart2js(
+      path.join('dev', 'integration_tests', 'web_compile_tests'),
+      path.join('lib', 'dart_io_import.dart'),
+    );
+  }
 }
 
 Future<void> _flutterBuildAot(String relativePathToApplication) async {