Add 'v' prefix to cm version

Author: klopfenstein-puzzle

.github/workflows/test-kubernetes.yaml

@@ -32,7 +32,7 @@ jobs:
     - name: Install cert-manager, patch upstream dns servers, wait for readiness
       run: |
         echo "Target cert-manager version: ${{ matrix.cm-version }}"
-        kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/${{ matrix.cm-version }}/cert-manager.yaml
+        kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v${{ matrix.cm-version }}/cert-manager.yaml
         # Patch cert-manager to use DNSimple's nameservers for faster propagation-checks
         kubectl patch deployment cert-manager -n cert-manager --type='json' -p='[{"op": "add", "path": "/spec/template/spec/containers/0/args/-", "value": "--dns01-recursive-nameservers=ns1.dnsimple.com:53"}]'
         kubectl wait --for=condition=available --timeout=600s deployment/cert-manager-webhook -n cert-manager