Update plugin support table for GHC 9.12.2

[fendor]

Demote hls-refactor-plugin to tier 2, as we regularly ship the initial GHC support without it.

[jhrcek]

LGTM

[maerten]

I noticed hls-fourmolu-plugin is listed as not supported by GHC 9.12.2.

However in a GHC 9.12.2 project with stack, it is possible to run stack install fourmolu and run it from the commandline without any issue.

$ stack --version
Version 3.3.1, Git revision 62d1bdf099c8c30634208f76cb4444f9896e4336 aarch64 hpack-0.37.0
$ stack ghc -- --version
The Glorious Glasgow Haskell Compilation System, version 9.12.2

$ which fourmolu
$HOME/.local/bin/fourmolu
$ fourmolu --version
fourmolu 0.18.0.0
using ghc-lib-parser 9.12.2.20250320

The only change needed to be able to run stack install fourmolu was adding the following to stack.yaml:

extra-deps:
  - ghc-lib-parser-9.12.2.20250320

From VSCode (actually Windsurf), formatting with fourmolu via HLS indeed didn't work.

2025-04-09T07:17:41.514403Z | Warning | No plugin handles this "textDocument/formatting" request.
[Error - 9:17:41 AM] Request textDocument/formatting failed.
  Message: No plugins are available to handle this SMethod_TextDocumentFormatting request.
 Plugins installed for this method, but not available to handle this request are:
cabal-fmt is not the formatting provider (fourmolu) you chose in your config.
  Code: -32601 

Unfortunately I using the external formatter in HLS doesn't work.

2025-04-09T07:24:36.976046Z | Warning | No plugin handles this "textDocument/formatting" request.
[Error - 9:24:36 AM] Request textDocument/formatting failed.
  Message: No plugins are available to handle this SMethod_TextDocumentFormatting request.
 Plugins installed for this method, but not available to handle this request are:
cabal-fmt is not the formatting provider (fourmolu) you chose in your config.
  Code: -32601 
2025-04-09T07:25:21.024204Z | Info | Live bytes: 201.67MB Heap size: 1050.67MB
2025-04-09T07:26:21.025567Z | Info | Live bytes: 201.67MB Heap size: 1050.67MB

But perhaps that is some misconfiguration on my end.

Just thought I would share, since at least fourmolu seems to be compatible with this GHC version :)

[fendor]

@maerten That's good to know, thanks!
This table is supposed to show the status quo! Right now, hls-fourmolu-plugin isn't supported, so that's why the table reflects it.