v1.20.0-pre2: Thancred Waters prerelease 2

* Makefile: Build robots2policy by @heftig in https://github.com/TecharoHQ/anubis/pull/699
* fix(default-config): off-by-one error in the default thresholds by @Xe in https://github.com/TecharoHQ/anubis/pull/701
* feat: implement imprint/impressum support by @Xe in https://github.com/TecharoHQ/anubis/pull/706
* fix(web/js): broken progress bar with slow algo by @yut23 in https://github.com/TecharoHQ/anubis/pull/673
* build(deps): bump the github-actions group with 3 updates by @dependabot in https://github.com/TecharoHQ/anubis/pull/708
* fix(lib): fix invalid response after success in Chrome by @Xe in https://github.com/TecharoHQ/anubis/pull/711