Bump the publish workflow's Sigstore action past the TUF root rotation

[lchoquel]

What

.github/workflows/publish-pypi.yml pinned sigstore/gh-action-sigstore-python@v3.0.0, whose bundled sigstore-python predates the Sigstore TUF trust-root rotation. The Sign the dists with Sigstore step now fails deterministically with:

tuf.api.exceptions.UnsignedMetadataError: root was signed by 0/3 keys

That step sits in the GitHub-release job, and PyPI publication is a separate job, so the failure mode is a version published to PyPI with no matching GitHub release or tag — exactly what happened to mthds-python v0.9.0 on the same pin.

The fix

One-line pin bump to v3.5.0, written as the SHA 790bc6befb9d733738f18d8f895854b453640ec9 to match how pipelex and mthds-python already carry it.

The SHA is not just supply-chain hygiene here: the GitHub Actions allowlist is managed at the enterprise level (above both the Pipelex and mthds-ai orgs) and already permits this exact SHA, added when pipelex was fixed. Any other version would first need an enterprise admin to allowlist its SHA.

Evidence

• The failure observed live on the same pin in mthds-python: run 33020408976, job Create GitHub Release with Changelog, step Sign the dists with Sigstore. Identical on re-run (attempt 2), so deterministic rather than transient.
• Reference fix already in the workspace: pipelex/.github/workflows/publish-pypi.yml:219, and mthds-python PR Release/v0.2.1 #46.

The downstream gh release upload "v$VERSION" dist/** step is unaffected — it globs whatever the signing step emits, and v3.x has produced .sigstore.json bundles throughout.

Closes L-260826-abe686

🤖 Generated with Claude Code

https://claude.ai/code/session_01MLDh2h2fJhY9E3YFHQ1Ana

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Summary by cubic

Bumps the publish workflow's Sigstore action from v3.0.0 to the SHA-pinned v3.5.0 so artifact signing no longer fails after the Sigstore TUF trust-root rotation. The old pin caused the "Sign the dists with Sigstore" step to fail deterministically, which published to PyPI without a matching GitHub release or tag.

• Writes the pin as SHA 790bc6befb9d733738f18d8f895854b453640ec9 because the enterprise Actions allowlist already permits that exact version.
• Adds the fix to the changelog.

^{Written for commit 6f58678. Summary will update on new commits.}

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge with no actionable regressions identified.

The updated action remains compatible with the workflow’s permissions, distribution globs, generated bundle naming, and downstream release upload.

_{Reviews (1): Last reviewed commit: "Bump the publish workflow's Sigstore act..." | Re-trigger Greptile}