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

This reverts commit 7b830d3.

Author: badmonster0

.github/workflows/_test.yml

@@ -33,7 +33,7 @@ jobs:
             cache: 'pip'
         - uses: actions/cache@v4
           with:
-            path: .venv/lib
+            path: .venv
             key: ${{ runner.os }}-pyenvlib-${{ steps.setup_python.outputs.python-version }}-${{ hashFiles('pyproject.toml') }}
             restore-keys: |
               ${{ runner.os }}-pyenvlib-${{ steps.setup_python.outputs.python-version }}-