[luci-go] remove hooks

I forgot to remove hooks in
https://chromium-review.googlesource.com/c/1475144

Bug: 851596
Change-Id: If055aa40b32b48dec12b1983219d2dd0928001a3
Reviewed-on: https://chromium-review.googlesource.com/c/1481276
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634215}
1 file changed