Mark e2e ios32 warmup test as nonflaky (#68511)

dev/devicelab/bin/tasks/flutter_gallery_sksl_warmup_ios32__transition_perf.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(createFlutterGalleryTransitionsPerfSkSLWarmupTest());
-}

dev/devicelab/manifest.yaml

@@ -229,21 +229,12 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["linux/android"]
 
-  flutter_gallery_sksl_warmup_ios32__transition_perf:
-    description: >
-      Measures the runtime performance of Flutter gallery transitions on iPhone4s
-      with SkSL shader warm-up.
-    stage: devicelab_ios
-    required_agent_capabilities: ["mac/ios32"]
-    flaky: true
-
   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
 
   backdrop_filter_perf__timeline_summary:
     description: >