docker_compose: 1.20.1 -> 1.21.2

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/docker-compose/versions.

These checks were done:

- built on NixOS
- /nix/store/z6xj749vplzm2x4hv93l34b41cb049kb-docker-compose-1.21.2/bin/.docker-compose-wrapped passed the binary check.
- /nix/store/z6xj749vplzm2x4hv93l34b41cb049kb-docker-compose-1.21.2/bin/docker-compose passed the binary check.
- 2 of 2 passed binary check by having a zero exit code.
- 0 of 2 passed binary check by having the new version present in output.
- found 1.21.2 with grep in /nix/store/z6xj749vplzm2x4hv93l34b41cb049kb-docker-compose-1.21.2
- directory tree listing: https://gist.github.com/6a7d68b839f5f57301d1c477e48ce88c
- du listing: https://gist.github.com/d1fd19f768c67e0cc36e885228ca138a