update dockerfile to add package findutils (#1657)

Dockerfile

@@ -19,9 +19,10 @@ RUN chmod +x /usr/local/bin/kubectl
 
 FROM alpine:3.20.0 AS run
 WORKDIR /opt/kube-bench/
-# add GNU ps for -C, -o cmd, and --no-headers support
+# add GNU ps for -C, -o cmd, --no-headers support and add findutils to get GNU xargs
 # https://github.com/aquasecurity/kube-bench/issues/109
-RUN apk --no-cache add procps
+# https://github.com/aquasecurity/kube-bench/issues/1656
+RUN apk --no-cache add procps findutils
 
 # Upgrading apk-tools to remediate CVE-2021-36159 - https://snyk.io/vuln/SNYK-ALPINE314-APKTOOLS-1533752
 # https://github.com/aquasecurity/kube-bench/issues/943