jackett: 0.8.1138 -> 0.8.1209 (#42999)

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

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

These checks were done:

- built on NixOS
- /nix/store/hlpqjm3nia27yrsvss57828qla6a1x5m-jackett-0.8.1209/bin/Jackett passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 0.8.1209 with grep in /nix/store/hlpqjm3nia27yrsvss57828qla6a1x5m-jackett-0.8.1209
- directory tree listing: https://gist.github.com/73cb9952f51705ba06c4c820c3466ffa
- du listing: https://gist.github.com/c6920225e6de6c9be6afa6799f4b17d6