nixos/thunderbird: add languagePacks config

[NicoWeio]

In analogy to #206698, I added a languagePacks option to Thunderbird to make it easier to set it up in another language without any manual intervention.
It would look something like this:

programs.thunderbird = {
  enable = true;
  languagePacks = [ "de" ];
  preferences = {
    "intl.locale.requested" = "de";
  };
};

This doesn't resolve the underlying issue #46569 that i18n.defaultLocale is not respected, but I imagine one could adopt something like the above code accessing the aforementioned i18n.defaultLocale into nixpkgs. I'm not sure if this is the correct way, though, as I'm too unfamiliar with Firefox/Thunderbird packaging. What I can say is that on Arch, the language packs go into usr/lib/thunderbird/extensions/langpack-de@thunderbird.mozilla.org.xpi, for example. My Arch system lists this language pack as explicitly installed, by the way; no idea how that came to be.

I hope this PR is actionable enough. As this is my first contribution to nixpkgs, any feedback would be very much appreciated!
I'll try running the tests in the coming days, though it'd be nice to know beforehand if this would even be considered.

Full disclosure: This is vibe-coded, but tested and cross-checked with #206698 as well as the current list of packs.

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

Maintainer pings

@booxter @lovesegfault @nbp @vcunat

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[NicoWeio]

nixpkgs-review result

Generated using nixpkgs-review.

Command: nixpkgs-review pr 473129
Commit: 08691f35f215750413d4ed3e5fdfe2cb22e69d7f

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x86_64-linux

⏩ 2 packages blacklisted:

• nixos-install-tools
• tests.nixos-functions.nixos-test

[NicoWeio]

Not sure if editing the PR description actually sent out the @mentions, so I'll drop them once more. Sorry if this ends up pinging you a second time.

@booxter @lovesegfault @nbp @vcunat

[booxter]

I do not use the NixOS module to configure Thunderbird so I can't really comment on whether it works. But the PR seems to be an honest replication of the Firefox PR.

I'd prefer if the list of languages would be fetched with an update script instead of requiring an update if/when a new language is added or removed. But Firefox module doesn't do it this way either, so probably not a blocker.

I hope someone more knowledgeable chimes in here though.

[bartoostveen]

LGTM, seems to work and list of available language packs exactly matches the directory listing at https://releases.mozilla.org/pub/thunderbird/releases/147.0.2/linux-x86_64/xpi/

[NicoWeio]

I agree that a script fetching the available languages would be nice, but it might take a while before I get around to creating one that's sufficiently reliable and satisfies Nixpkgs standards, so I'd love to see this merged before.

[bartoostveen]

I mean, if you want a script, here is a simple one line proof of concept:

curl https://releases.mozilla.org/pub/thunderbird/releases/147.0.2/linux-x86_64/xpi/ | htmlq -t a | tail -n +2 | sed 's/\.xpi//g'

[NicoWeio]

@bartoostveen Thanks, I didn't know about htmlq!
I think I have built a working update script now, but the Thunderbird update.nix calls the Firefox one. Assuming we want to keep it that way, is it really fine to touch Firefox in this PR?

[bartoostveen]

IMHO it does not really matter, but I think it's still better to make a separate PR that touches both Firefox and Thunderbird.