Downgrade e2e tests to Kubernetes v1.20.7

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

.github/workflows/e2e.yaml

@@ -27,7 +27,7 @@ jobs:
         uses: engineerd/setup-kind@v0.5.0
         with:
           version: v0.11.1
-          image: kindest/node:v1.21.1@sha256:69860bda5563ac81e3c0057d654b5253219618a22ec3a346306239bba8cfa1a6
+          image: kindest/node:v1.19.11@sha256:07db187ae84b4b7de440a73886f008cf903fcf5764ba8106a9fd5243d6f32729
           config: .github/kind/config.yaml # disable KIND-net
       - name: Setup envtest
         uses: fluxcd/pkg/actions/envtest@main