fix: code-samples/serving/hello-world/helloworld-python/Dockerfile to…

… reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN12-GLIBC-5927132
- https://snyk.io/vuln/SNYK-DEBIAN12-GLIBC-5927132
- https://snyk.io/vuln/SNYK-DEBIAN12-GLIBC-6210098
- https://snyk.io/vuln/SNYK-DEBIAN12-GLIBC-6210098
- https://snyk.io/vuln/SNYK-DEBIAN12-OPENSSL-6032384

code-samples/serving/hello-world/helloworld-python/Dockerfile

@@ -1,6 +1,6 @@
 # Use the official lightweight Python image.
 # https://hub.docker.com/_/python
-FROM python:3.7-slim
+FROM python:3.13.0b3-slim
 
 # Allow statements and log messages to immediately appear in the Knative logs
 ENV PYTHONUNBUFFERED True