Revert "Make tests more resilient to Skia gold failures and refactor flutter_goldens for extensive technical debt removal (#140101)" (#141814)

Reverts https://github.com/flutter/flutter/pull/140101

That PR somehow made non-matching gold tests not fail at HEAD.

Fixes https://github.com/flutter/flutter/issues/141880
- Blocked by https://github.com/flutter/flutter/issues/140169
  - https://github.com/flutter/flutter/pull/141427