dev-python/setuptools: update METADATA for CVE-2025-47273

This change updates the METADATA file to reflect that CVE-2025-47273
is mitigated by a patch.

BUG=b:456337451
TEST=none

Change-Id: I31b8af2e0431fa5322172adcaf6455972e79ce68
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/7275619
Auto-Submit: Greg Edelston <gredelston@google.com>
Tested-by: Greg Edelston <gredelston@google.com>
Commit-Queue: Greg Edelston <gredelston@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>