fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN12-ZLIB-6008963
- https://snyk.io/vuln/SNYK-DEBIAN12-GLIBC-1546991
- https://snyk.io/vuln/SNYK-DEBIAN12-KRB5-1549480
- https://snyk.io/vuln/SNYK-DEBIAN12-PAM-6178914
- https://snyk.io/vuln/SNYK-DEBIAN12-UTILLINUX-2401083

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.9-slim as base
+FROM python:3.14.0a3-slim as base
 
 ENV \
     # Keeps Python from generating .pyc files in the container