test_source_encoding crashed with STATUS_ACCESS_VIOLATION on GHA Windows x86

[vstinner]

GHA Windows x86:

0:11:25 load avg: 11.30 [289/467/1] test_source_encoding worker non-zero exit code (Exit code 3221225477 (STATUS_ACCESS_VIOLATION))
Windows fatal exception: access violation

Thread 0x00000724 (most recent call first):
  <no Python frame>

build: https://github.com/python/cpython/actions/runs/6407820510/job/17395506542?pr=110297 (or PR #110297 which only adds code, but don't change anything in existing code, so the PR is unrelated)

[vstinner]

I enhanced regrtest to try to get more information (test worker process stdout+stderr) about this crash: issue gh-110367.

I close this issue for now. I will reopen it if the bug comes back, I hope, with more information next time.