chore: add XRootD on macos (#1399)

Author: ianna

.github/workflows/build-test.yml

@@ -59,7 +59,7 @@ jobs:
           ssh -o StrictHostKeyChecking=no localhost echo "ssh connection successful"
 
       - name: Install XRootD
-        if: runner.os != 'macOS' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: |
           conda env list
           mamba install xrootd