fix: remove redundant autocmd for formatter

lua/core/events.lua

@@ -47,6 +47,7 @@ au({ 'WinEnter', 'InsertLeave' }, {
 au({ 'WinLeave', 'InsertEnter' }, {
   group = group,
   callback = function()
+    -- Keep it on NvimTree to show current file
     if vim.bo.filetype == 'NvimTree' then
       return
     end

lua/plugins/language-manager.lua

@@ -293,13 +293,16 @@ end
 function M.lint.setup()
   vim.api.nvim_create_autocmd({ 'BufReadPre', 'BufNewFile' }, {
     group = M.group,
+    once = true,
     callback = function()
       local lint = require('lint')
       lint.linters_by_ft = (M.general and M.general.linters_by_ft) or {}
       vim.api.nvim_create_autocmd({ 'BufEnter', 'BufWritePost', 'InsertLeave' }, {
         group = vim.api.nvim_create_augroup('language-manager.lint', { clear = true }),
         callback = function()
-          lint.try_lint()
+          if vim.bo.modifiable then
+            lint.try_lint()
+          end
         end,
       })
     end,
@@ -307,16 +310,10 @@ function M.lint.setup()
 end
 
 function M.format.setup()
-  vim.api.nvim_create_autocmd('BufWritePre', {
+  require('conform').setup({
-    group = M.group,
+    formatters_by_ft = (M.general and M.general.formatters_by_ft) or {},
-    once = true,
+    default_format_opts = { stop_after_first = true, lsp_format = 'fallback' },
-    callback = function()
+    format_on_save = { timeout_ms = 500 },
-      require('conform').setup({
-        format_on_save = { timeout_ms = 500, lsp_format = 'fallback' },
-        default_format_opts = { stop_after_first = true },
-        formatters_by_ft = (M.general and M.general.formatters_by_ft) or {},
-      })
-    end,
   })
 end