Cache pip without setup-python

.github/workflows/CI.yml

@@ -31,19 +31,15 @@ jobs:
           - x64
     steps:
       - uses: actions/checkout@v4
-      - name: Hack setup-python cache
-        # Create an empty requirements.txt if this file (or pyproject.toml) doesn't exist.
-        # This has been reported at: https://github.com/actions/setup-python/issues/807
-        # In the future this might be addressed by: https://github.com/actions/setup-python/pull/762
-        # or https://github.com/actions/setup-python/issues/751
-        if: hashFiles('**/requirements.txt', '**/pyproject.toml') == ''
-        run: |
-          touch ./requirements.txt
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.12'
-          cache: 'pip' # caching pip dependencies
+          python-version: '3'
+      - uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip
       - run: pip install matplotlib
+        shell: bash
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}
@@ -62,19 +58,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Hack setup-python cache
-      # Create an empty requirements.txt if this file (or pyproject.toml) doesn't exist.
-      # This has been reported at: https://github.com/actions/setup-python/issues/807
-      # In the future this might be addressed by: https://github.com/actions/setup-python/pull/762
-      # or https://github.com/actions/setup-python/issues/751
-      if: hashFiles('**/requirements.txt', '**/pyproject.toml') == ''
-      run: |
-        touch ./requirements.txt
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.12'
-          cache: 'pip' # caching pip dependencies
+          python-version: '3'
+      - uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip
       - run: pip install matplotlib
+        shell: bash
       - uses: julia-actions/setup-julia@v2
         with:
           version: '1'