Remove download_binaries.py from DEPS

This step is no longer necessary after https://codereview.chromium.org/2775913002/

Bug: 705072
Change-Id: Ia58cbe9e6cb450d832de24dbb5122597efc3e571
Reviewed-on: https://chromium-review.googlesource.com/459442Reviewed-by: Magnus Jedvert <magjed@chromium.org>
Commit-Queue: Tom Anderson <thomasanderson@google.com>

DEPS

@@ -424,15 +424,6 @@ hooks = [
                 '-d', 'src/tools/luci-go/linux64',
     ],
   },
-  {
-    # Pull sanitizer-instrumented third-party libraries if requested via
-    # GYP_DEFINES.
-    # See src/third_party/instrumented_libraries/scripts/download_binaries.py.
-    # TODO(kjellander): Update comment when GYP is completely cleaned up.
-    'name': 'instrumented_libraries',
-    'pattern': '\\.sha1',
-    'action': ['python', 'src/third_party/instrumented_libraries/scripts/download_binaries.py'],
-  },
   {
     'name': 'clang_format_merge_driver',
     'pattern': '.',