fix(terminal): avoid E676 after failed :wqa (#40620)

src/nvim/ex_cmds.c

@@ -2132,6 +2132,7 @@ void do_wqall(exarg_T *eap)
         && channel_job_running((uint64_t)buf->b_p_channel)) {
       no_write_message_buf(buf);
       error++;
+      continue;
     } else if (!bufIsChanged(buf) || bt_dontwrite(buf)) {
       continue;
     }

test/functional/terminal/buffer_spec.lua

@@ -16,6 +16,7 @@ local testprg = n.testprg
 local write_file = t.write_file
 local command = n.command
 local matches = t.matches
+local not_matches = t.not_matches
 local exec_lua = n.exec_lua
 local sleep = vim.uv.sleep
 local fn = n.fn
@@ -239,6 +240,9 @@ describe(':terminal buffer', function()
 
   it('requires bang (!) to close a running job #15402', function()
     eq('Vim(wqall):E948: Job still running (add ! to end the job)', pcall_err(command, 'wqall'))
+    command('redir => g:wqall_out | silent! wqall | redir END')
+    matches('E948:', api.nvim_get_var('wqall_out'))
+    not_matches('E676:', api.nvim_get_var('wqall_out'))
     for _, cmd in ipairs({ 'bdelete', '%bdelete', 'bwipeout', 'bunload' }) do
       matches(
         '^Vim%('