ci: swith to nightly in emsdk

Author: ManonMarchand

.github/workflows/emscripten.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.12'
+          python-version: '3.13'
       - run: pip install pyodide-build
       - shell: bash
         run: |
@@ -34,5 +34,7 @@ jobs:
           pip install maturin
           # rustup install nightly-2025-02-01
           # rustup default nightly-2025-02-01
+          rustup install nightly
+          rustup default nightly
           rustup target add wasm32-unknown-emscripten
           maturin build --target wasm32-unknown-emscripten -i 3.12