[ci] Remove pip-install phase (not really useful)

.gitlab-ci.yml

@@ -147,17 +147,6 @@ quality:
   script:
       - pixi_run qa-ci,default qa-ci,qa
 
-pip-install:
-  stage: qa
-  cache:
-    key: pip-install
-    paths:
-      - _cache/uv
-  script:
-    - pixi global install 'python=3.12.*' uv
-    - uv venv --python ${PIXI_HOME}/bin/python
-    - uv pip install --dry-run --editable .
-
 tests:
   stage: test
   parallel: