Update README since the library is not used

Change-Id: I5570c02b2633c0556d7e7ab8b48c426e59792686
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/5301338
Reviewed-by: Srinivas Sista <srinivassista@chromium.org>
Auto-Submit: Mikhail Khokhlov <khokhlov@google.com>
Commit-Queue: Srinivas Sista <srinivassista@chromium.org>

tracing/third_party/devscripts/README.chromium

diff --git a/tracing/third_party/devscripts/README.chromium b/tracing/third_party/devscripts/README.chromium
index 3ce4c19..2838349 100644
--- a/tracing/third_party/devscripts/README.chromium
+++ b/tracing/third_party/devscripts/README.chromium
@@ -2,7 +2,7 @@
 URL: http://anonscm.debian.org/gitweb/?p=devscripts/devscripts.git
 Version: 2.12.4
 Security Critical: no
-Shipped: yes
+Shipped: no
 License: GPL 2.0
 
 Description: