Bump google-github-actions/auth from 0.4.4 to 0.6.0 (sigstore#1501)

Bumps [google-github-actions/auth](https://github.com/google-github-actions/auth) from 0.4.4 to 0.6.0.
- [Release notes](https://github.com/google-github-actions/auth/releases)
- [Changelog](https://github.com/google-github-actions/auth/blob/main/CHANGELOG.md)
- [Commits](google-github-actions/auth@c6c2290...8d12589)

---
updated-dependencies:
- dependency-name: google-github-actions/auth
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build.yaml

@@ -48,7 +48,7 @@ jobs:
         run: go get golang.org/x/tools/cmd/goimports
 
       - name: Set up Cloud SDK
-        uses: google-github-actions/auth@c6c22902f6af237edb96ede5f25a00e864589b2f # v0.4.4
+        uses: google-github-actions/auth@8d125895b958610ec414ca4dae010257eaa814d3 # v0.4.4
         with:
           workload_identity_provider: 'projects/498091336538/locations/global/workloadIdentityPools/githubactions/providers/sigstore-cosign'
           service_account: '[email protected]'