Remove download_binaries.py from DEPS

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

BUG=chromium:705072

Review-Url: https://codereview.chromium.org/2774043002
Cr-Commit-Position: refs/heads/master@{#44252}

DEPS

@@ -250,16 +250,6 @@ hooks = [
         '--running-as-hook',
     ],
   },
-  {
-    # Pull sanitizer-instrumented third-party libraries if requested via
-    # GYP_DEFINES.
-    'name': 'instrumented_libraries',
-    'pattern': '\\.sha1',
-    'action': [
-        'python',
-        'v8/third_party/instrumented_libraries/scripts/download_binaries.py',
-    ],
-  },
   {
     # Update the Windows toolchain if necessary.
     'name': 'win_toolchain',