build(deps): bump the ci group with 2 updates

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


Updates `korthout/backport-action` from 2.1.0 to 2.1.1
- [Release notes](https://github.com/korthout/backport-action/releases)
- [Commits](cb79e4e5f4...08bafb375e)

Updates `sigstore/cosign-installer` from 3.1.2 to 3.2.0
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](11086d2504...1fc5bd396d)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/backport.yaml

@@ -17,7 +17,7 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Create backport PRs
-        uses: korthout/backport-action@cb79e4e5f46c7d7d653dd3d5fa8a9b0a945dfe4b # v2.1.0
+        uses: korthout/backport-action@08bafb375e6e9a9a2b53a744b987e5d81a133191 # v2.1.1
         # 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

@@ -36,7 +36,7 @@ jobs:
       - name: Setup Syft
         uses: anchore/sbom-action/download-syft@78fc58e266e87a38d4194b2137a3d4e9bcaf7ca1 # v0.14.3
       - name: Setup Cosign
-        uses: sigstore/cosign-installer@11086d25041f77fe8fe7b9ea4e48e3b9192b8f19 # v3.1.2
+        uses: sigstore/cosign-installer@1fc5bd396d372bee37d608f955b336615edf79c8 # v3.2.0
       - name: Setup Kustomize
         uses: fluxcd/pkg/actions/kustomize@main
       - name: Login to GitHub Container Registry
@@ -155,7 +155,7 @@ jobs:
           --path="./flux-system" \
           --source=${{ github.repositoryUrl }} \
           --revision="${{ github.ref_name }}@sha1:${{ github.sha }}"
-      - uses: sigstore/cosign-installer@11086d25041f77fe8fe7b9ea4e48e3b9192b8f19 # v3.1.2
+      - uses: sigstore/cosign-installer@1fc5bd396d372bee37d608f955b336615edf79c8 # v3.2.0
       - name: Sign manifests
         env:
           COSIGN_EXPERIMENTAL: 1