fix(spectral-language-server): build directly from source

[williamboman]

The npm package is an unofficial one, and it seems to be relying on a
build script (broken) to execute during installation, instead of pre-packaging
it.

Fixes #463.

[hawkinchina]

I have the same problem(lua lsp ) . how can i download the vscode-lua-v3.5.6-darwin-x64.vsix directly. and config manually.?

Failed
◍ lua-language-server
Downloading file "https://github.com/sumneko/vscode-lua/releases/download/v3.5.6/vscode-lua-v3.5.6-darwin-x64.vsix"...
...acker/start/mason.nvim/lua/mason-core/installer/init.lua:113: ...er/start/mason.nvim/lua/mason-core/managers/std/init.lua:52: Failed to download file "https://github.com/sumneko/vscode-lua/releases/download/v3.5.6/vscode-lua-v3.5.6-darwin-x64.vsix".
spawn: curl failed with exit code 60 and signal 0. curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.se/docs/sslcerts.html

  curl failed to verify the legitimacy of the server and therefore could not
  establish a secure connection to it. To learn more about this situation and
  how to fix it, please visit the web page mentioned above.

[hawkinchina]

disable curl Certificate Verification of fetch.lua in mason.nvim with -k/--insecure option. it can work.