Add pip and tox caching to CI workflows

- Add pip caching to Python setup steps in test and lint workflows
- Add tox environment caching to reduce setup time
- Cache key includes tox.ini, setup.py, and pyproject.toml hashes

Author: he-james

.github/workflows/lint.yml

@@ -86,6 +86,7 @@ jobs:
         if: ${{ steps.counter.outputs.count > 0 }}
         with:
           python-version: '3.9'
+          cache: 'pip'
       - run: pip install mypy==1.5.1
         if: ${{ steps.counter.outputs.count > 0 }}
       - run: mypy ${{ steps.filter.outputs.python_files }} --follow-imports=silent --ignore-missing-imports

.github/workflows/test.yml

@@ -26,6 +26,14 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.py }}
+          cache: 'pip'
+      - name: Cache tox environments
+        uses: actions/cache@v3
+        with:
+          path: .tox
+          key: tox-${{ matrix.os }}-${{ matrix.py }}-${{ hashFiles('tox.ini', 'setup.py', 'pyproject.toml') }}
+          restore-keys: |
+            tox-${{ matrix.os }}-${{ matrix.py }}-
       - name: Install tox
         run: python -m pip install tox
       - uses: actions/checkout@v3
@@ -35,6 +43,7 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.py }}
+          cache: 'pip'
       - name: Setup test suite
         run: |
           sudo apt-get update && sudo apt-get install -y portaudio19-dev