BUG: Bump CI pixi version to 0.39.3

Author: thewtex

.github/workflows/pixi-test.yml

@@ -15,7 +15,7 @@ jobs:
 
       - uses: prefix-dev/setup-pixi@v0.8.1
         with:
-          pixi-version: v0.37.0
+          pixi-version: v0.39.3
           frozen: true
 
       - name: Run tests