fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-UBUNTU2310-GNUTLS28-6069047
- https://snyk.io/vuln/SNYK-UBUNTU2310-PERL-6085371
- https://snyk.io/vuln/SNYK-UBUNTU2310-PROCPS-5972730
- https://snyk.io/vuln/SNYK-UBUNTU2310-PROCPS-5972730
- https://snyk.io/vuln/SNYK-UBUNTU2310-TAR-6096092

Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:rolling
+FROM ubuntu:23.10
 
 COPY validate-jekyll-deploy.sh /validate-jekyll-deploy.sh
 RUN apt -y update && apt -y install sudo ruby-full build-essential zlib1g-dev