DEPS: update luci-go

This is mainly for isolate cas upload optimization in
https://crrev.com/c/2612794

Bug: 1157476
Change-Id: I9d1fe45388271fceb6485349f67c8de168faa2f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2626668Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@google.com>
Commit-Queue: Yoshisato Yanagisawa <yyanagisawa@google.com>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842851}

DEPS

@@ -177,7 +177,7 @@ vars = {
   # luci-go CIPD package version.
   # Make sure the revision is uploaded by infra-packagers builder.
   # https://ci.chromium.org/p/infra-internal/g/infra-packagers/console
-  'luci_go': 'git_revision:67aba6e3373bb0b9e3ef9871362045736cd29b6e',
+  'luci_go': 'git_revision:16e6d735358b0166f06fd2e4daa0da4cff9918e9',
 
   # This can be overridden, e.g. with custom_vars, to build clang from HEAD
   # instead of downloading the prebuilt pinned revision.