Missing package in repo for Debian 11 bullseye

Hello, I try to install gitlab-runner under Debian 11 Bullseye by script. But repository for bulleye dos not contains gitlab-runner package.

curl -L "https://packages.gitlab.com/install/repositories/runner/gitlab-runner/script.deb.sh" | sudo bash
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The repository is setup! You can now install packages.

root@grunner-shell:~# apt-get-update
Hit:1 http://security.debian.org/debian-security bullseye-security InRelease
Hit:2 http://deb.debian.org/debian bullseye InRelease
Hit:3 http://deb.debian.org/debian bullseye-updates InRelease
Hit:4 https://packages.gitlab.com/runner/gitlab-runner/debian bullseye InRelease
Reading package lists... Done

root@grunner-shell:~# apt search gitlab-runner
Sorting... Done
Full Text Search... Done

But I successfully installed gitlab-runner, when changed "bullseye" to "buster" in /etc/apt/sources.list.d/runner_gitlab-runner.list

root@grunner-shell:~# sed -i -e 's/bullseye/buster/g' /etc/apt/sources.list.d/runner_gitlab-runner.list
root@grunner-shell:~# apt-get update
Hit:1 http://deb.debian.org/debian bullseye InRelease
Hit:2 http://security.debian.org/debian-security bullseye-security InRelease
Hit:3 http://deb.debian.org/debian bullseye-updates InRelease
Get:4 https://packages.gitlab.com/runner/gitlab-runner/debian buster InRelease [23.5 kB]
Ign:5 https://packages.gitlab.com/runner/gitlab-runner/debian buster/main amd64 Packages
Get:5 https://packages.gitlab.com/runner/gitlab-runner/debian buster/main amd64 Packages [17.7 kB]
Fetched 41.1 kB in 3s (12.1 kB/s)
Reading package lists... Done

root@grunner-shell:~# apt search gitlab-runner
Sorting... Done
Full Text Search... Done
gitlab-runner/buster 14.7.0 amd64
  GitLab Runner```