Update dependency conftest to v0.64.0

Author: renovate-bot

modules/satoshi/k8s-tool-versions

@@ -7,7 +7,7 @@ amtool 0.25.0
 
 #asdf:plugin add conftest
 #renovate: depName=open-policy-agent/conftest
-conftest 0.55.0
+conftest 0.64.0
 
 #asdf:plugin add go-jsonnet https://github.com/sirikon/asdf-go-jsonnet.git
 #renovate: depName=google/go-jsonnet