Remove ineffectual entries for official mac builders from builders.pyl

Bug: v8:11264
Change-Id: I9563ede8e4a5f1eea17e5ee93a8ab8609c3000b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2614426
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71968}

infra/testing/builders.pyl

@@ -1329,30 +1329,6 @@
       {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
     ],
   },
-  'V8 Official Mac ARM64': {
-    'swarming_dimensions': {
-      'cpu': 'x86-64',
-      'os': 'Mac-10.15',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default', 'shards': 2},
-      {'name': 'v8testing', 'shards': 2},
-      {'name': 'v8testing', 'variant': 'extra'},
-    ],
-  },
-  'V8 Official Mac ARM64 Debug': {
-    'swarming_dimensions': {
-      'cpu': 'x86-64',
-      'os': 'Mac-10.15',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default', 'shards': 2},
-      {'name': 'v8testing', 'shards': 4},
-      {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
-    ],
-  },
   'V8 Mac64 ASAN': {
     'swarming_dimensions': {
       'cpu': 'x86-64',