chore(deps): update helm release rook-ceph to v1.15.6 (#249)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

manifest/infrastructure/rook-ceph/helmfile.yaml

@@ -9,7 +9,7 @@ releases:
   - name: rook-ceph-operator
     namespace: rook-ceph
     chart: rook-release/rook-ceph
-    version: v1.15.5
+    version: v1.15.6
     values:
       - env/common/operator.yaml
   - name: rook-ceph-cluster