mypy

c1464a9e - Revert "Fix disappearing errors when re-running dmypy check (#14835)" (#15179)

Revert "Fix disappearing errors when re-running dmypy check (#14835)" (#15179) This reverts commit a9ee618f3a941098b24156eb499db5684fcfc261. The original fix doesn't work in all cases. Reverting it since fixing remaining issues is non-trivial, and it's better not to include regressions or partially implemented features in mypy 1.3. See #9655 for context.