maturin needs nightly (#30)

Reviewed-on: https://codeberg.org/nd-project/nd/pulls/30
Co-authored-by: Matthew Scroggs <matthew.w.scroggs@gmail.com>
Co-committed-by: Matthew Scroggs <matthew.w.scroggs@gmail.com>

Author: mscroggs

.github/workflows/run-tests.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
       - name: Set up Python
         uses: actions/setup-python@v4
         with: