Add experimental conda build upload step

Author: avcopan

.github/workflows/build.yml

@@ -20,4 +20,11 @@ jobs:
       # Build
       - name: Build
         run: |
-          pixi run build
+          pixi run build
+
+      # Upload
+      - name: Upload
+        run: |
+          pixi run upload
+        env:
+          ANACONDA_API_KEY: ${{ secrets.ANACONDA_API_KEY }}