b1bcd7acba
This adds a new `programs.bash.logout` option which configures the Bash
logout script.
Carefully note that the stock Bash does not support a global logout
script and only supports user-local logout scripts in `~/.bash_logout`.
However, Nixpkgs patches Bash to support a global `/etc/bash_logout`
script here:
ee0fecd318/pkgs/shells/bash/5.nix (L48)
… and the `programs.bash.logout` option configures that logout script.