fix: custom/hardened-alpine/infra/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE316-BUSYBOX-6913410
- https://snyk.io/vuln/SNYK-ALPINE316-BUSYBOX-6913410

custom/hardened-alpine/infra/Dockerfile

@@ -1,6 +1,6 @@
 # This Dockerfile contains the hardened alpine image that can be used in litmus components.
 # It is also made non-root with default litmus directory.
-FROM alpine:3.16.9
+FROM alpine:3.20.3
 
 LABEL maintainer="LitmusChaos"