Remove failing 32-bit iOS benchmarks (#76800)

dev/devicelab/bin/tasks/flutter_gallery_ios32__start_up.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:flutter_devicelab/tasks/perf_tests.dart';
-import 'package:flutter_devicelab/framework/adb.dart';
-import 'package:flutter_devicelab/framework/framework.dart';
-
-Future<void> main() async {
-  deviceOperatingSystem = DeviceOperatingSystem.ios;
-  await task(createFlutterGalleryStartupTest());
-}

dev/devicelab/bin/tasks/flutter_gallery_sksl_warmup__transition_perf_e2e_ios32.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:flutter_devicelab/tasks/perf_tests.dart';
-import 'package:flutter_devicelab/framework/adb.dart';
-import 'package:flutter_devicelab/framework/framework.dart';
-
-Future<void> main() async {
-  deviceOperatingSystem = DeviceOperatingSystem.ios;
-  await task(createFlutterGalleryTransitionsPerfSkSLWarmupE2ETest());
-}

dev/devicelab/manifest.yaml

@@ -65,20 +65,6 @@ tasks:
 
   # iOS on-device tests
 
-  flutter_gallery_sksl_warmup__transition_perf_e2e_ios32:
-    description: >
-      Measures the runtime performance of Flutter gallery transitions on iPhone4s
-      with SkSL shader warm-up with e2e.
-    stage: devicelab_ios
-    required_agent_capabilities: ["mac/ios32"]
-    flaky: true
-
-  flutter_gallery_ios32__start_up:
-    description: >
-      Measures the startup time of the Flutter Gallery app on 32-bit iOS (iPhone 4S).
-    stage: devicelab_ios
-    required_agent_capabilities: ["mac/ios32"]
-
   native_ui_tests_ios32:
     description: >
       Run native XCUITests on 32-bit iOS (iPhone 4S).