ci: avoid installing pre-releases to reduce complexity

Author: consideRatio

.github/workflows/test.yml

@@ -60,20 +60,21 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install pytest
           pip install -r requirements.txt
+          pip list
+
       - name: Install nodejs dependencies
         run: |
           sudo npm install -g configurable-http-proxy
 
-      # We need to check compatibility with different versions of the JH
-      # API, including latest development.  For that, we also need to
-      # pull in the dependencies of that old JH version (but we don't
-      # need conda/npm for our tests).
+      # We need to check compatibility with different versions of the JH API,
+      # including latest development.  For that, we also need to pull in the
+      # development dependencies of that old JH version (but we don't need
+      # conda/npm for our tests).
       - name: install JupyterHub
         run: |
-          git clone --quiet --branch ${{ matrix.JHUB_VER }} https://github.com/jupyterhub/jupyterhub.git jupyterhub
-          pip install --pre -r jupyterhub/dev-requirements.txt
-          pip install --upgrade pytest
-          pip install --pre -e jupyterhub
+          git clone --quiet --branch ${{ matrix.JHUB_VER }} https://github.com/jupyterhub/jupyterhub.git ./jupyterhub
+          pip install -r ./jupyterhub/dev-requirements.txt
+          pip install ./jupyterhub
 
       - name: pytest
         run: |