Fixed docker image and added comments after review

Author: bmispelon

.github/workflows/tests.yml

@@ -15,6 +15,8 @@ permissions:
 
 env:
   DJANGO_SETTINGS_MODULE: tracdjangoplugin.settings_tests
+  # passlib has a conditional import for `crypt` which is going away in python 3.13
+  # and therefore throwing warnings
   PYTHONWARNINGS: >
     error,
     default:::passlib.utils,

Dockerfile

@@ -1,5 +1,5 @@
 # pull official base image
-FROM python:3.12-slim-bookworm
+FROM python:3.11-slim-bookworm
 
 # set work directory
 WORKDIR /code

requirements.txt

@@ -5,7 +5,9 @@ psycopg2==2.9.9 --no-binary=psycopg2
 Django==4.2.16
 libsass==0.23.0
 
-# Optional Trac dependencies that make DeprecationWarning go away
+# Optional Trac dependencies that make DeprecationWarning go away.
+# When upgrading Trac or Python, check if these dependencies are still needed
+# by uninstalling them and running the test suite (or CI) with PYTHONWARNINGS=error
 multipart==1.1.0
 passlib==1.7.4