fix: custom/hardened-alpine/experiment/Dockerfile to reduce vulnerabi…

…lities

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/experiment/Dockerfile

@@ -1,7 +1,7 @@
 # This Dockerfile contains the hardened alpine image with all the
 # litmus experiment dependencies installed.
 # It is also made non-root, sudo-enabled with default litmus directory.
-FROM alpine:3.16.9
+FROM alpine:3.19
 
 LABEL maintainer="LitmusChaos"