Hide check_test_cases warnings on the CI

We aren't paying attention to the warnings. So hide them and save log size.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index ba37e33..1a2b10a 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -833,7 +833,7 @@
     else
         opt=''
     fi
-    tests/scripts/check_test_cases.py $opt
+    tests/scripts/check_test_cases.py -q $opt
     unset opt
 }