replace roslyn with omnisharp

init.lua

@@ -619,6 +619,8 @@ require('lazy').setup({
         -- But for many setups, the LSP (`ts_ls`) will work just fine
         -- ts_ls = {},
 
+        omnisharp = {},
+
         stylua = {}, -- Used to format Lua code
 
         -- Special Lua Config, as recommended by neovim help docs
@@ -661,7 +663,7 @@ require('lazy').setup({
       local ensure_installed = vim.tbl_keys(servers or {})
       vim.list_extend(ensure_installed, {
         -- You can add other tools here that you want Mason to install
-        'roslyn',
+        'omnisharp',
       })
 
       require('mason-tool-installer').setup { ensure_installed = ensure_installed }