chore(deps): bump the ci group across 1 directory with 2 updates

Bumps the ci group with 2 updates in the / directory: [korthout/backport-action](https://github.com/korthout/backport-action) and [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer).


Updates `korthout/backport-action` from 3.2.0 to 3.2.1
- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](korthout/backport-action@436145e...0193454)

Updates `sigstore/cosign-installer` from 3.9.0 to 3.9.1
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](sigstore/cosign-installer@fb28c2b...398d4b0)

---
updated-dependencies:
- dependency-name: korthout/backport-action
  dependency-version: 3.2.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: ci
- dependency-name: sigstore/cosign-installer
  dependency-version: 3.9.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: ci
...

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

Author: dependabot[bot]

.github/workflows/backport.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Create backport PRs
-        uses: korthout/backport-action@436145e922f9561fc5ea157ff406f21af2d6b363 # v3.2.0
+        uses: korthout/backport-action@0193454f0c5947491d348f33a275c119f30eb736 # v3.2.1
         # xref: https://github.com/korthout/backport-action#inputs
         with:
           # Use token to allow workflows to be triggered for the created PR

.github/workflows/release.yaml

@@ -50,7 +50,7 @@ jobs:
             **/go.mod
       - uses: docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392 # v3.6.0
       - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1
-      - uses: sigstore/cosign-installer@fb28c2b6339dcd94da6e4cbcbc5e888961f6f8c3 # v3.9.0
+      - uses: sigstore/cosign-installer@398d4b0eeef1380460a10c8013a76f728fb906ac # v3.9.1
       - uses: anchore/sbom-action/download-syft@9246b90769f852b3a8921f330c59e0b3f439d6e9 # v0.20.1
       - name: Docker login ghcr.io
         uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0