When a new release is promoted to either the beta or stable channel, the corresponding field in infra/config/lib/release_branches/branches.json should be kept up to date, and re-generate the repository's config by executing infra/config/main.star.
After editing the protobuf, run the command:
protoc --descriptor_set_out=./branches.bin ./branches.proto
And check in the updated branches.bin file.