chore(deps): update slsa-framework/slsa-github-generator action to v2.1.0

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
slsa-framework/slsa-github-generator	action	minor	v2.0.0 -> v2.1.0

---

Release Notes

slsa-framework/slsa-github-generator (slsa-framework/slsa-github-generator)

v2.1.0

Compare Source

v2.1.0: Sigstore Bundles for Generic Generator and Go Builder

The workflows generator_generic_slsa3.yml and builder_go_slsa3.yml
have been updated to produce signed Sigstore Bundles, just like all the other builders
that use the BYOB framework.

The workflow logs will now print a LogIndex, rather than a LogUUID. Both are equally searchanble on
https://search.sigstore.dev/.

v2.1.0: Vars context recorded in provenance

• Updated: GitHub vars context is now recorded in provenance for the generic and
  container generators. The vars context cannot affect the build in the Go
  builder so it is not recorded.

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

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

---

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

[renovate]

Branch automerge failure

This PR was configured for branch automerge. However, this is not possible, so it has been raised as a PR instead.