Use silversquirl/zig-flake

[silversquirl]

Shameless plug ofc, but my flake has a number of advantages over zig-overlay :)

• very frequent updates - each zig version should be available in the flake within half an hour of being published to ziglang.org
• fetches from community mirrors - this increases availability when ziglang.org has downtime, and also avoids DoSing ZSF
• includes a setup hook and a makePackage helper to make packaging extremely easy
• includes a dependency fetcher that doesn't need a deps.nix (just update a single depsHash instead)
• zero dependencies (no pointless flake-utils ^^')
• actively maintained - zig-overlay has open PRs that haven't even been given feedback in over a year

[silversquirl]

also, a note on versioning: it would be very nice if zls chose a specific nightly version to use (eg. zig_0_16_0_dev_9) rather than simply following the nightly alias. this means other flakes that depend on zls can have it follow their copy of zig-flake, and still run nix flake update without any fear of zls breaking due to the new version.

This would be much appreciated even if you choose to reject this PR and stick with zig-overlay! ^-^

[Techatrix]

Took me some time but I managed to convince myself to agree with switching to silversquirl/zig-flake.

• fetches from community mirrors - this increases availability when ziglang.org has downtime, and also avoids DoSing ZSF

Some time after this PR has been opened, zig-overlay did start fetching from community mirrors but they used fetchurl with multiple urls which are fetched in order so it just always tries https://pkg.machengine.org/zig. Your flake appears to fetch from mirrors at random which is nice. I do have a possible issue about how to deal with community-mirrors.txt which can be found in silversquirl/zig-flake#2. Would be nice to get that resolved before switching.

• includes a setup hook and a makePackage helper to make packaging extremely easy

• includes a dependency fetcher that doesn't need a deps.nix (just update a single depsHash instead)

That sure looks convenient. But I'd like to minimize the amount of things that have been offloaded to a different flake so packaging ZLS and fetching it's dependencies should remain as is. Just with zig-overlay, a different flake can provide us with Zig but that's it.

I have implemented an updated version of the ZLS flake here:
https://github.com/zigtools/zls/tree/techatrix/nix

I also pinned the Zig version just like you suggested and made some other improvements. Let me know if think that's an acceptable solution or you have further suggestions.