Update export-mcad.yaml

updates to v3 upload artifact

.github/workflows/export-mcad.yaml

@@ -84,7 +84,7 @@ jobs:
 
     - name: Upload DXFs as Artifacts
       if: github.event_name != 'release'
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v3
       with:
         name: Feeder-DXFs
         path: ~/Feeder-DXFs.zip