Revert "Add iannucci to depot_tools owners"

This reverts commit b6a0b58b.

Reason for revert: we should have a good coverage now within just
chops source. You are welcome to stay owner if you'd like tho.

Original change's description:
> 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>

Change-Id: I0a5138d8a119d2d2699e04857c95e6f2875aaac0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3657058Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

OWNERS

@@ -3,7 +3,6 @@ set noparent
 ajp@google.com
 aravindvasudev@google.com
 gavinmak@google.com
-iannucci@chromium.org
 sokcevic@google.com
 
 per-file ninja*=thakis@chromium.org