Upgrade to python 3.12 and use built-in cache feature

https://github.com/actions/setup-python?tab=readme-ov-file#caching-packages-dependencies

.github/actions/prepare-python/action.yml

@@ -13,15 +13,8 @@ runs:
     - name: "Setup python"
       uses: actions/setup-python@v5
       with:
-        python-version: 3.9
-
-    - name: "Check for cached dependencies"
-      uses: actions/cache@v4
-      with:
-        path: ~/.cache/pip
-        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
-        restore-keys: |
-          ${{ runner.os }}-pip-
+        python-version: 3.12
+        cache: 'pip'
 
     - name: "Install and upgrade pip"
       shell: bash