Remove Python 3.9 compatibility (I love match/case)

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

.gitlab-ci.yml

@@ -2,14 +2,6 @@ stages:
   - test
   - quality-assurance
 
-py39:
-  stage: test
-  image: python:3.9-alpine
-  before_script:
-    - apk add --no-cache libmagic
-    - pip install tox --no-cache-dir
-  script: tox -e py39
-
 py310:
   stage: test
   image: python:3.10-alpine

tox.ini

@@ -1,6 +1,5 @@
 [tox]
 envlist =
-    py39
     py310
     py311