Small fix.

Author: oleburghardt

.github/workflows/regression.yml

@@ -226,10 +226,10 @@ jobs:
       fail-fast: false
       matrix:
         testscript: ['serial_regression_AD.py']
-      include:
-        - testscript: 'serial_regression_AD.py'
-          #tag: TagNoMP, check:
-          tag: NoMPI
+        include:
+          - testscript: 'serial_regression_AD.py'
+            #tag: TagNoMP, check:
+            tag: NoMPI
     steps:
       - name: Pre Cleanup
         uses: docker://ghcr.io/su2code/su2/test-su2:240320-1536