siso: do not have _is_subcommand_present print to stdout.

Bug: b/455433899
Change-Id: I20a840669538c1a48a645226b949b37f6a6a6964
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/7205887
Reviewed-by: Junji Watanabe <jwata@google.com>
Commit-Queue: Alex Ovsienko <ovsienko@google.com>

tests/siso_test.py

@@ -70,7 +70,7 @@ ninja --failure_verbose=false -k=0
     @mock.patch('siso.subprocess.call')
     def test_is_subcommand_present(self, mock_call):
 
-        def side_effect(cmd):
+        def side_effect(cmd, *_, **__):
             if cmd[2] in ['collector', 'ninja']:
                 return 0
             return 2