Drop tools/gyp from dependencies

Reland of cl https://webrtc-review.googlesource.com/c/src/+/6763. In
the mean time, chromium scripts have been fixed to not depend on
gyp.MSVSVersion, see
https://chromium-review.googlesource.com/c/chromium/src/+/1104163

Bug: webrtc:6323
Change-Id: I6dbbbbf1216a94d5ed6ab69e2a5e78f215951793
Reviewed-on: https://webrtc-review.googlesource.com/84128
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23657}
diff --git a/DEPS b/DEPS
index a5a4289..0f6e8d3 100644
--- a/DEPS
+++ b/DEPS
@@ -186,8 +186,6 @@
     Var('chromium_git') + '/chromium/deps/yasm/patched-yasm.git' + '@' + 'b98114e18d8b9b84586b10d24353ab8616d4c5fc',
   'src/tools':
     Var('chromium_git') + '/chromium/src/tools' + '@' + '59c08146e77c9b27dbaef0703ff144d43a050cd0',
-  'src/tools/gyp':
-    Var('chromium_git') + '/external/gyp.git' + '@' + 'd61a9397e668fa9843c4aa7da9e79460fe590bfb',
   'src/tools/swarming_client':
     Var('chromium_git') + '/infra/luci/client-py.git' + '@' +  Var('swarming_revision'),