Possible upstream lib nvchecker

[blaggacao]

There is a possible upstream lib candidate at https://github.com/lilydjwg/nvchecker

Let me know what you think (of using that instead of internal version checker implementations)?

Suggestion for the "related work section": https://github.com/berberman/nvfetcher (uses nvchecker)

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Edit: It looks like nvchecker currently vastly out-competes nix-update on available plugins

nvchecker plugins vs. nix-update plugins.