report nightly Zig versions that have no compatible ZLS version yet

[Techatrix]

The /v1/zls/select-version request has the ability to report that a given Zig nightly version has no compatible ZLS version (yet) with the following response:

{
  "code": 2,
  "message": "Zig ${ZIG_VERSION} has no compatible ZLS build (yet)"
}

Unfortunately, for this feature to work, the ZLS CI needed to report failed Zig versions back to the release-worker which was never implemented. So this error was never actually reported at anytime.

The response should also mention what the latest Zig version is that is supported by ZLS so that version management tools could suggest to install that version instead.