fix: examples/cloud_run_http/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-KRB5-7411315

Author: snyk-bot

examples/cloud_run_http/Dockerfile

@@ -1,6 +1,6 @@
 # Use the official Python image.
 # https://hub.docker.com/_/python
-FROM python:3.7-slim
+FROM python:3.13.3-slim
 
 # Copy local code to the container image.
 ENV APP_HOME /app