Add iannucci to depot_tools owners

Change-Id: Ic85057a6075ba398e4800edffd183f5e2eccd259
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3440929
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>

OWNERS

@@ -3,6 +3,7 @@ set noparent
 ajp@google.com
 aravindvasudev@google.com
 gavinmak@google.com
+iannucci@chromium.org
 jochen@chromium.org
 sokcevic@google.com