Bump the ci group across 1 directory with 2 updates

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


Updates `docker/build-push-action` from 6.13.0 to 6.14.0
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](ca877d9245...0adf995921)

Updates `sigstore/cosign-installer` from 3.8.0 to 3.8.1
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](c56c2d3e59...d7d6bc7722)

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

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

.github/workflows/nightly.yaml

@@ -22,7 +22,7 @@ jobs:
         id: buildx
         uses: docker/setup-buildx-action@f7ce87c1d6bead3e36075b2ce75da1f6cc28aaca # v3.9.0
       - name: Build multi-arch container image
-        uses: docker/build-push-action@ca877d9245402d1537745e0e356eab47c3520991 # v6.13.0
+        uses: docker/build-push-action@0adf9959216b96bec444f325f1e493d4aa344497 # v6.14.0
         with:
           push: false
           builder: ${{ steps.buildx.outputs.name }}

.github/workflows/release.yml

@@ -68,7 +68,7 @@ jobs:
             type=raw,value=${{ steps.prep.outputs.VERSION }}
       - name: Publish images
         id: build-push
-        uses: docker/build-push-action@ca877d9245402d1537745e0e356eab47c3520991 # v6.13.0
+        uses: docker/build-push-action@0adf9959216b96bec444f325f1e493d4aa344497 # v6.14.0
         with:
           sbom: true
           provenance: true
@@ -79,7 +79,7 @@ jobs:
           platforms: linux/amd64,linux/arm/v7,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-      - uses: sigstore/cosign-installer@c56c2d3e59e4281cc41dea2217323ba5694b171e # v3.8.0
+      - uses: sigstore/cosign-installer@d7d6bc7722e3daa8354c50bcb52f4837da5e9b6a # v3.8.1
       - name: Sign images
         env:
           COSIGN_EXPERIMENTAL: 1