Improve neovim diagnostics

Do not use phpstan via language server, I use Ale for that.
Do not underline diagnostic issues, use same as ALE.

home/files/phpactor/phpactor.yml

@@ -2,7 +2,7 @@
 "code_transform.refactor.generate_accessor.upper_case_first": true
 "language_server_completion.trim_leading_dollar": true
 "language_server.diagnostics_on_update": false
-"language_server_phpstan.enabled": true
+"language_server_phpstan.enabled": false
 "indexer.follow_symlinks": true
 "indexer.exclude_patterns":
   - "**\/var\/**\/*"

home/programs/neovim.nix

@@ -303,8 +303,7 @@ in {
       type = "lua";
       config = ''
         vim.diagnostic.config({
-          virtual_text = false,
-          signs = false,
+          underline = false,
         })
 
         require('lspconfig').phpactor.setup({