delete cache

.github/workflows/run_test.yml

@@ -17,15 +17,6 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
-      - uses: actions/cache@v1
-        with:
-          path: ~/.cache/pip
-          key: >
-            ${{ runner.os }}-pip-
-            ${{ hashFiles('**/requirements.txt') }}-
-            ${{ hashFiles('**/requirements_test.txt') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip