Fix IAC vulnerability issue

Author: cx-Margarita-LevitM

Dockerfile

@@ -1,15 +1,14 @@
 # Use AST Base image
 FROM checkmarx/ast-cli:2.3.22@sha256:64cb2c7c244a342f0fe6308654cdac2bee35d26c35985bb97294575c9c192054
 
-# Docker actions must be run by the default Docker user (root).
-USER root
-
 # Copy the entrypoint script and properties used for the action
 COPY entrypoint.sh /app/entrypoint.sh
 COPY cleanup.sh /app/cleanup.sh
 
 RUN chmod +x /app/entrypoint.sh \
     && chmod +x /app/cleanup.sh
 
+# Docker actions must be run by the default Docker user (root).
+USER nonroot
 
 HEALTHCHECK NONE