Another try at Python action setup

.forgejo/workflows/build.yaml

@@ -51,12 +51,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Set up Python toolchain
-        uses: https://github.com/actions/setup-python@v5
+        uses: actions/setup-python@v5
         with:
-          python-version: "3.13"
           cache: pip
       - name: Set up Python environment
-        run: pip install -r requirements.txt
+        run: python3 -m pip install -r requirements.txt
       - name: Set up Rust
         uses: https://github.com/dtolnay/rust-toolchain@stable
       - name: Build Rust code