[pointer_interceptor] Remove implements from app-facing package

[bparrishMines]

Dart unit tests started failing for pointer_interceptor due to the implements tag in the app facing package. This plugin is federated for ios and web, so it looks like the error message is valid.

Plugin pointer_interceptor:ios provides an implementation for pointer_interceptor_platform_interface and also references a default implementation for pointer_interceptor_ios, which is currently not supported. Ask the maintainers of pointer_interceptor to either remove the implementation via `implements: pointer_interceptor_platform_interface` or avoid referencing a default implementation via `platforms: ios: default_package: pointer_interceptor_ios`.


00:00 +0 -1: loading /b/s/w/ir/x/w/packages/packages/pointer_interceptor/pointer_interceptor/test/tests_exist_elsewhere_test.dart [E]                                                                  
  Error: Please resolve the plugin pubspec errors
  package:flutter_tools/src/base/common.dart 10:3          throwToolExit
  package:flutter_tools/src/flutter_plugins.dart 1214:5    resolvePlatformImplementation
  package:flutter_tools/src/flutter_plugins.dart 1418:55   generateMainDartWithPluginRegistrant
  ===== asynchronous gap ===========================
  package:flutter_tools/src/test/test_compiler.dart 163:9  TestCompiler._onCompilationRequest
  
  TimeoutException after 0:12:00.000000: Test timed out after 12 minutes.
  package:test_api/src/backend/invoker.dart 338:28  Invoker._handleError.<fn>
  dart:async/zone.dart 1391:47                      _rootRun
  dart:async/zone.dart 1301:19                      _CustomZone.run
  package:test_api/src/backend/invoker.dart 336:10  Invoker._handleError
  package:test_api/src/backend/invoker.dart 291:9   Invoker.heartbeat.<fn>.<fn>
  dart:async/zone.dart 1399:13                      _rootRun
  dart:async/zone.dart 1301:19                      _CustomZone.run
  package:test_api/src/backend/invoker.dart 290:38  Invoker.heartbeat.<fn>
  dart:async-patch/timer_patch.dart 18:15           Timer._createTimer.<fn>
  dart:isolate-patch/timer_impl.dart 398:19         _Timer._runTimers
  dart:isolate-patch/timer_impl.dart 429:5          _Timer._handleMessage
  dart:isolate-patch/isolate_patch.dart 184:12      _RawReceivePort._handleMessage
  

To run this test again: /b/s/w/ir/x/w/flutter/bin/cache/dart-sdk/bin/dart test 

This removes the tag and does a manual roll.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter. (Unlike the flutter/flutter repo, the flutter/packages repo does use dart format.)
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[ditman]

LGTM, good fix! This must be a new check, because federation happened a while ago (?)

[ditman]

Publishing for this change could be omitted, I think?

[bparrishMines]

Yea, I wasn't sure whether this affected clients or not. I did it just in case.

[Gustl22]

This must be a new check, because federation happened a while ago (?)

Yes, this error message was introduced in flutter/flutter#145258, because the exisiting plugin resolution did allow this despite having an inconsistent dependency tree.

Thanks for applying this!

[ditman]

@Gustl22 thanks for adding this, I totally didn't catch the inconsistency during manual review!