test-runner: Don't bother enabling IWD_GENL_DEBUG

IWD_GENL_DEBUG is not generally useful anymore as it just prints a
hexdump of the raw data on the socket.  The messages are quite verbose
and spam test-runner logs for little utility.

tools/test-runner

@@ -693,9 +693,6 @@ class Namespace:
 		if self.is_verbose('iwd-tls'):
 			env['IWD_TLS_DEBUG'] = '1'
 
-		if self.is_verbose('iwd-genl'):
-			env['IWD_GENL_DEBUG'] = '1'
-
 		if self.is_verbose('iwd-acd'):
 			env['IWD_ACD_DEBUG'] = '1'