ops(workflow): limit cache folder for Python venv to lib

Author: badmonster0

.github/workflows/_test.yml

@@ -32,10 +32,10 @@ jobs:
             cache: 'pip'
         - uses: actions/cache@v4
           with:
-            path: .venv
-            key: ${{ runner.os }}-pythonenv-${{ matrix.python-version }}-${{ hashFiles('pyproject.toml') }}
+            path: .venv/lib
+            key: ${{ runner.os }}-pyenvlib-${{ matrix.python-version }}-${{ hashFiles('pyproject.toml') }}
             restore-keys: |
-              ${{ runner.os }}-pythonenv-${{ matrix.python-version }}-
+              ${{ runner.os }}-pyenvlib-${{ matrix.python-version }}-
         - name: Setup venv
           run: |
             python -m venv .venv