Add free-threaded Python to the CI

.github/workflows/main.yml

@@ -75,6 +75,14 @@ jobs:
             python-version: "3.12"
             platform: { os: "ubuntu-latest", python-architecture: "x64", rust-target: "x86_64-unknown-linux-gnu" }
             msrv: "MSRV"
+          - rust: stable
+            python-version: "3.14t"
+            platform: { os: "ubuntu-latest", python-architecture: "x64", rust-target: "x86_64-unknown-linux-gnu" }
+            msrv: "Free-Threaded"
+          - rust: stable
+            python-version: "3.14t"
+            platform: { os: "macOS-14", python-architecture: "arm64", rust-target: "aarch64-apple-darwin" }
+            msrv: "Free-Threaded"
           # Test future versions of Rust and Python
           - rust: beta
             python-version: "3.14" # upgrade to 3.15-dev when the release candidate is available

.github/workflows/wheels.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           python-version: '3.12'
       - name: Install deps
-        run: pip install -U setuptools-rust build
+        run: pip install -U maturin>=1.9.0,<2.0 build
       - name: Build sdist
         run: python -m build --sdist
       - uses: actions/upload-artifact@v4

src/generators.rs

@@ -1778,7 +1778,7 @@ pub fn karate_club_graph(py: Python, multigraph: bool) -> PyResult<graph::PyGrap
     })
 }
 
-#[pymodule]
+#[pymodule(gil_used = false)]
 pub fn generators(_py: Python, m: &Bound<PyModule>) -> PyResult<()> {
     m.add_wrapped(wrap_pyfunction!(cycle_graph))?;
     m.add_wrapped(wrap_pyfunction!(directed_cycle_graph))?;

src/lib.rs

@@ -462,7 +462,7 @@ create_exception!(
     "Graph is not bipartite"
 );
 
-#[pymodule]
+#[pymodule(gil_used = false)]
 fn rustworkx(py: Python<'_>, m: &Bound<PyModule>) -> PyResult<()> {
     m.add("__version__", env!("CARGO_PKG_VERSION"))?;
     m.add("InvalidNode", py.get_type::<InvalidNode>())?;