Update dependency open-policy-agent/conftest to v0.64.0

Author: renovate[bot]

confbatstest/Dockerfile_build

@@ -30,7 +30,7 @@ ARG OC_VERSION=4.20.1
 # renovate: datasource=github-releases depName=open-policy-agent/opa
 ARG OPA_VERSION=v1.8.0
 # renovate: datasource=github-releases depName=open-policy-agent/conftest
-ARG CONFTEST_VERSION=v0.59.0
+ARG CONFTEST_VERSION=v0.64.0
 # renovate: datasource=github-releases depName=instrumenta/kubeval
 ARG KUBEVAL_VERSION=latest