Fix path filter for template test PR job (#62485)

Author: wtgodbe

.azure/pipelines/template-tests-pr.yml

@@ -16,7 +16,7 @@ pr:
     - release/*
   paths:
     include:
-    - src/ProjectTemplates/**/*
+    - src/ProjectTemplates/*
 
 variables:
 - name: _UseHelixOpenQueues