Add PyO3 iterator fix references

[cookesan]

Adds PyO3 iterator fix references to GHSA-36hh-v3qg-5jq4.

Audit refresh, July 8, 2026:

• Confirmed the live PR is open, ready for review, merge-clean, and the visible advisory check is green.
• Rechecked the merge-base diff: exactly one advisory JSON file changes (advisories/github-reviewed/2026/06/GHSA-36hh-v3qg-5jq4/GHSA-36hh-v3qg-5jq4.json), JSON parses, git diff --check passes, and the exact-head worktree is clean.
• Revalidated the added public references and package-version evidence in the diff; all resolve through their source site or registry.

[cookesan]

Rechecked on 2026-07-07 after updating this PR.

• The patch adds the PyO3 iterator fix commit reference and the PyO3 0.29.0 fixed release reference; it does not change affected ranges, package metadata, severity, or review metadata.
• The fix commit resolves to 3d48a540572a86548a8f670ea96fa486036d476a.
• The v0.29.0 release notes list the BoundTupleIterator and BoundListIterator nth_back out-of-bounds read fix.
• v0.29.0 contains the fix commit, and crates.io API metadata confirms pyo3 0.29.0 is published and not yanked.

The advisory processing check is green and the PR remains clean.