workflows: add charybdis

.github/workflows/oragono.yml

@@ -24,17 +24,12 @@ jobs:
         path: |
           ~/.cache
           $GITHUB_WORKSPACE/oragono
-        key: ${{ runner.os }}
+        key: ${{ runner.os }}-oragono
 
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install pre-commit pytest
-        pip install -r requirements.txt
-
-    - name: Lint
-      run: |
-        pre-commit run -a
+        pip install pytest -r requirements.txt
 
     - name: Checkout Oragono
       uses: actions/checkout@v2