Remove obsolete instruction on how to roll gn

This file contains obsolete instruction on how to roll gn, remove
it to avoid confusion on the part of the reader.

Bug: none
Change-Id: Iad26f372b188c78a88eb76741bab170d58f41987
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/4483
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>

docs/update_binaries.md

diff --git a/docs/update_binaries.md b/docs/update_binaries.md
deleted file mode 100644
index d3e3bbc..0000000
--- a/docs/update_binaries.md
+++ /dev/null
@@ -1,5 +0,0 @@
-# How to update the GN binaries that Chromium uses.
-
-Any committer should be able to do a roll by running
-[//tools/gn/bin/roll_gn.py](../bin/roll_gn.py) on Linux or Mac.
-