remove shebang from quiet

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/scripts/quiet/quiet b/tests/scripts/quiet/quiet
index 8f83d07..00e2f63 100755
--- a/tests/scripts/quiet/quiet
+++ b/tests/scripts/quiet/quiet
@@ -1,5 +1,3 @@
-#! /usr/bin/env bash
-#
 # Copyright The Mbed TLS Contributors
 # SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 #