bpo-38291: Reset DeprecationWarning filters in test_typing io and re

[Fidget-Spinner]

https://bugs.python.org/issue38291

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @Fidget-Spinner for commit 5190297 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[gvanrossum]

I suppose we went too quick here? I’m not sure what this does (it’s been a long time since I played with warnings) but if this is blocking other PRs I am happy to merge it.

[Fidget-Spinner]

I suppose we went too quick here? I’m not sure what this does (it’s been a long time since I played with warnings) but if this is blocking other PRs I am happy to merge it.

Luckily this isn't blocking other PRs, buildbot failures only block releases AFAIK. As Sebastian mentioned on the bpo issue, it's an Azure pipelines problem. The specific pipeline is only run after a commit is made. Even with the test-with-buildbots label, I'm unable to recreate the conditions for the failure on a PR. At best, this fix is a hunch which I have no way of verifying or reproducing locally.

This fix wasn't clear to me too, until I read this part of the warnings docs:
https://docs.python.org/3/library/warnings.html#testing-warnings

[bedevere-bot]

@gvanrossum: Please replace # with GH- in the commit message next time. Thanks!