Update BUILD files with Gazelle.

Change-Id: Id01354ec90cac9b6d780db4a7ffe9f4c599934e3
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/371973
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
diff --git a/golden/go/indexer/BUILD.bazel b/golden/go/indexer/BUILD.bazel
index c2aea6a..1f3e159 100644
--- a/golden/go/indexer/BUILD.bazel
+++ b/golden/go/indexer/BUILD.bazel
@@ -51,6 +51,7 @@
         "//golden/go/clstore",
         "//golden/go/clstore/mocks",
         "//golden/go/code_review",
+        "//golden/go/diff",
         "//golden/go/diff/mocks",
         "//golden/go/diffstore/mocks",
         "//golden/go/digest_counter",