chore(deps): update dependency open-policy-agent/conftest to v0.56.0 in testing/dockerfile (main) (#5055)

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

Author: renovate[bot]

testing/Dockerfile

@@ -16,7 +16,7 @@ RUN case $(uname -m) in x86_64|amd64) ARCH="amd64" ;; aarch64|arm64|armv7l) ARCH
 
 # Install conftest
 # renovate: datasource=github-releases depName=open-policy-agent/conftest
-ENV CONFTEST_VERSION=0.55.0
+ENV CONFTEST_VERSION=0.56.0
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 RUN case $(uname -m) in x86_64|amd64) ARCH="x86_64" ;; aarch64|arm64|armv7l) ARCH="arm64" ;; esac && \
     curl -LOs https://github.com/open-policy-agent/conftest/releases/download/v${CONFTEST_VERSION}/conftest_${CONFTEST_VERSION}_Linux_${ARCH}.tar.gz && \