Add caching and test different style of env import

.gitea/workflows/release.yml

@@ -20,13 +20,16 @@ jobs:
         with:
           python-version: "3.11"
 
-      - name: Setup tox
-        run: pip install tox>=4.16
+      - name: Cache pip packages
+        uses: actions/cache@v2
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}-${{ hashFiles('test-requirements.txt') }}
 
       - name: Run tox
         run: |
-          source .env.example
-          tox
+          pip install tox>=4.16
+          source .env.example && tox
 
   build:
     runs-on: ubuntu-latest