chore(deps): update sigstore/cosign-installer action to v3.6.0

| datasource  | package                   | from   | to     |
| ----------- | ------------------------- | ------ | ------ |
| github-tags | sigstore/cosign-installer | v3.5.0 | v3.6.0 |

Author: stackable-bot

template/.github/workflows/build.yml.j2

@@ -351,7 +351,7 @@ jobs:
       # default value in the makefile if called from this action, but not otherwise (i.e. when called locally).
       # This is needed for the HELM_REPO variable.
       - name: Install cosign
-        uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # v3.5.0
+        uses: sigstore/cosign-installer@4959ce089c160fddf62f7b42464195ba1a56d382 # v3.6.0
       - name: Install syft
         uses: anchore/sbom-action/download-syft@e8d2a6937ecead383dfe75190d104edd1f9c5751 # v0.16.0
       - name: Build Docker image and Helm chart
@@ -396,7 +396,7 @@ jobs:
       OCI_REGISTRY_SDP_CHARTS_USERNAME: "robot$sdp-charts+github-action-build"
     steps:
       - name: Install cosign
-        uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # v3.5.0
+        uses: sigstore/cosign-installer@4959ce089c160fddf62f7b42464195ba1a56d382 # v3.6.0
       - name: Checkout
         uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
         with: