Switch gating test to run test_xmlsec.sh

Test was previously only pointing to the mellon tests.  Fixing gating to
run the test_xmlsec.sh script so that xmlsec specific tests also get
run.

Resolves: rhbz#1977300

tests/scripts/run_tests.sh

@@ -9,4 +9,4 @@ if [ ! -d /tmp/artifacts ]; then
 fi
 
 ./setup.sh
-./test_mellon.sh
+./test_xmlsec.sh