Remove deprecated `use_relative_hooks = True` from DEPS file.

According to gclient, `use_relative_hooks` is deprecated, since
it was merged into `use_relative_paths`, so delete that line.

Change-Id: Iaa20b8756c4d9f49f9a73dc6b13a46798ab2423d
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2316056
Commit-Queue: Benedikt Meurer <[email protected]>
Commit-Queue: Paul Lewis <[email protected]>
Auto-Submit: Benedikt Meurer <[email protected]>
Reviewed-by: Paul Lewis <[email protected]>
diff --git a/DEPS b/DEPS
index 7ebe5bb..9ee504b 100644
--- a/DEPS
+++ b/DEPS
@@ -3,7 +3,6 @@
 # found in the LICENSE file.
 
 use_relative_paths = True
-use_relative_hooks = True
 
 vars = {
   'build_url': 'https://chromium.googlesource.com/chromium/src/build.git',