ENH: Explicitly specify to run 1 test at a time

This is the default, but be explicit.  Trigger
CI running on dashboard.

Author: hjmjohnson

.github/workflows/ci.yml

@@ -82,7 +82,7 @@ jobs:
       - name: Test
         run: |
             cd build/castxml-prefix/src/castxml-build
-            ctest --output-on-failure
+            ctest -j 1 --output-on-failure
 
       #####################################
       # Package the resulting castxml binary