chore(deps): pin dependencies

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
Swatinem/rust-cache	action	pinDigest	→ 6323deb
actions/checkout	action	pinDigest	→ 3d3c42e

---

Warning

Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • At any time (no schedule defined)
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

👻 Immortal: This PR will be recreated if closed unmerged. Get config help if that's undesired.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[pierre-warnier]

Green on all fourteen checks. This is a correct catch: the two actions in the Fuzz targets job were added after the digest pinning went in, so they were still on tags.

I cannot merge it myself — the token this account uses has no workflow scope, so GitHub refuses any merge that touches .github/workflows/. Needs a maintainer, or Renovate's automerge.