Try to fix Python dependency installation

.forgejo/workflows/build.yaml

@@ -8,6 +8,9 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
       - name: Install Python dependencies
+        with:
+          python-version: "3.13"
+          cache: "pip"
         run: pip install -r requirements.txt
       - name: Set up Rust
         uses: https://github.com/actions-rust-lang/setup-rust-toolchain@v1