autoninja: skip RBE wrapper for -t tool invocations for siso

ninja tools don't need an RBE environment active, so avoid an
unnecessary delay and noisy output when something like autoninja -t
commands is invoked.

Change-Id: Ieb58dee56b15968dcac9483ff41be25544f02470
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5991650
Auto-Submit: Fumitoshi Ukai <ukai@google.com>
Commit-Queue: Junji Watanabe <jwata@google.com>
Reviewed-by: Junji Watanabe <jwata@google.com>

autoninja.py

@@ -261,7 +261,7 @@ def _main_inner(input_args, build_id, should_collect_logs=False):
             # Build ID consistently used in other tools. e.g. Reclient, ninjalog.
             os.environ.setdefault("SISO_BUILD_ID", build_id)
             if use_remoteexec:
-                if use_reclient:
+                if use_reclient and not t_specified:
                     return reclient_helper.run_siso(
                         [
                             'siso',