fix: content/actions/reference/workflows-and-actions/dockerfile-support.md to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN9-GLIBC-356506
- https://snyk.io/vuln/SNYK-DEBIAN9-GLIBC-356506
- https://snyk.io/vuln/SNYK-DEBIAN9-GLIBC-356506
- https://snyk.io/vuln/SNYK-DEBIAN9-DPKG-2847943
- https://snyk.io/vuln/SNYK-DEBIAN9-GLIBC-356686

Author: snyk-bot

content/actions/reference/workflows-and-actions/dockerfile-support.md

@@ -60,7 +60,7 @@ ENTRYPOINT ["sh", "-c", "echo $GITHUB_SHA"]
 
 ```dockerfile
 # Container image that runs your code
-FROM debian:9.5-slim
+FROM debian:13.0-slim
 
 # Copies your code file from your action repository to the filesystem path `/` of the container
 COPY entrypoint.sh /entrypoint.sh