Update build.yml

Updating to actions/upload-artifact@v4

Author: phargogh

.github/workflows/build.yml

@@ -71,7 +71,7 @@ jobs:
                     --privileged \
                     quay.io/singularity/singularity:v3.10.3 pull docker://ghcr.io/${{ github.repository_owner }}/${{ env.CONTAINER_NAME }}:${{ env.DATESTAMP_VERSION }}
 
-            - uses: actions/upload-artifact@v3
+            - uses: actions/upload-artifact@v4
               with:
                   path: |
                       *.sif