ankisyncd-rs: allow specifying initial username and password

[anpandey]

anki-sync-server-rs exposes the ANKISYNCD_USERNAME and ANKISYNCD_PASSWORD env variables for initializing the auth db with a username and a password, which this exposes to make the config more reproducible for a single-user use case.

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[martinetd]

oh, this module doesn't define meta.maintainers so I never got pinged (and the folks who created it ages before me neither)

ankisyncd-rs is officially no longer maintained so the ankisyncd module have been deprecated and will be removed in master after 2405 is released (in 3 weeks, replaced by #257692 ), so this is probably no longer really worth merging, but sure why not - it might make sense to merge for the 24.05 branch if it's helpful.