Pin maven repo test to a revision

Since the "master" branch has been renamed to "main", let's make sure we pin to
a revision and fix if there is other rename going on.

Signed-off-by: Chmouel Boudjnah <chmouel@redhat.com>

maven/tests/run.yaml

@@ -17,6 +17,8 @@ spec:
       params:
         - name: url
           value: https://github.com/spring-projects/spring-petclinic
+        - name: revision
+          value: "d367e2b4b41a2de899b0f438bc984a7c1c011b77"
         - name: subdirectory
           value: ""
         - name: deleteExisting