ci(python-wasm): add setup-pixi step

Author: thewtex

.github/workflows/python-wasm.yml

@@ -31,6 +31,8 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - uses: prefix-dev/[email protected]
+
       - name: Set up Python ${{ env.python-version }}
         uses: actions/setup-python@v5
         with: