project.config: require LUCI to pass on release branches

By now LUCI provides more complete test coverage compared to the old
build system. For example, it's capable of catching problems that are
only apparent when using the exact minimum required bootstrap version.

Require LUCI to be used on release branches sooner than elsewhere,
to avoid the possibility of a problem that could've been caught in
pre-submit but wasn't due to the old trybots being selected, such
as the recent case in go.dev/issue/63339.

Change-Id: I314f0167433741a61a3bb814fb63e8dd88064b39
Reviewed-on: https://go-review.googlesource.com/c/All-Projects/+/537476
Reviewed-by: Heschi Kreinick <heschi@google.com>

project.config

diff --git a/project.config b/project.config
index 9cbf121..656877c 100644
--- a/project.config
+++ b/project.config
@@ -204,6 +204,12 @@
 	submittableIf = is:false
 	overrideIf = label:TryBot-Bypass=MAX
 	canOverrideInChildProjects = true
+[submit-requirement "LUCI-Pass"]
+	description = Changes on release branches must pass LUCI unless TryBot-Bypass+1 is set.
+	applicableIf = branch:\"^refs/heads/release-branch.+\"
+	submittableIf = label:LUCI-TryBot-Result=MAX
+	overrideIf = label:TryBot-Bypass=MAX
+	canOverrideInChildProjects = true
 [submit-requirement "No-Unresolved-Comments"]
 	description = Changes that have unresolved comments are not submittable, unless overriden by adding the hashtag allow-unresolved-comments.
 	applicableIf = has:unresolved