ci: renovate ignores python related version updates (#268)

This pull request updates the `.github/renovate.json` configuration to
add new rules for dependency management, specifically targeting
Python-related dependencies and base images. The new rules are currently
disabled, allowing for future flexibility in how Renovate handles Python
interpreter and base image updates.

Python dependency management:

* Added a host rule to disable updates from the test PyPI registry
(`test.pypi.org`).
* Added a rule to ignore Python interpreter version updates managed by
`poetry`, with the rule disabled for now.

Docker image management:

* Added a rule to ignore updates to Python base images in Dockerfiles,
including common package names, and set the rule as disabled.

Author: a-klos

.github/renovate.json

@@ -66,6 +66,12 @@
       "matchManagers": ["poetry", "pip_requirements"],
       "addLabels": ["python"]
     },
+    {
+      "description": "Ignore Python interpreter version updates",
+      "matchManagers": ["poetry"],
+      "matchDepNames": ["python"],
+      "enabled": false
+    },
     {
       "description": "Label Node.js dependencies",
       "matchManagers": ["npm"],
@@ -76,6 +82,12 @@
       "matchManagers": ["dockerfile", "docker-compose"],
       "addLabels": ["docker"]
     },
+    {
+      "description": "Ignore Python base image updates in Dockerfiles",
+      "matchManagers": ["dockerfile"],
+      "matchPackageNames": ["python", "docker.io/library/python", "library/python"],
+      "enabled": false
+    },
     {
       "description": "Label Helm charts",
       "matchManagers": ["helm-requirements", "helm-values", "helmv3"],