[Fire162]

Fixes #287.

Instantiate ValidationAbortedError on demand and clear its traceback when caught so aborted validations do not keep frames alive on the error. Keep validation_aborted_error defined at module scope for backwards compatibility.

[Cito]

Thanks a lot for the quick PR, @Fire162! It fixes the leak reported in #287, but I went with a slightly different fix in #289:

• The aborted error could still keep the frames alive through __context__ when the error limit is reached while an exception is being handled, e.g. when OverlappingFieldsCanBeMergedRule reports an exceeded comparison budget.
• The custom __init__ would no longer accept the positional arguments of GraphQLError.
• The module-level validation_aborted_error is not exported, so it can be removed.

It would be great if you could take a look at #289 as well. I'm going to release 3.3.1 with it shortly, and you will be mentioned in the release notes. I'll close this PR when #289 is merged.

[Cito]

The fix from #289 has been released in GraphQL-core 3.3.1, so I'm closing this one. Thanks again for your PR, @Fire162!