fix(events): always allow some events to be nested (#32706)

Always allow the following four events to be nested, as they may contain
important information, and are triggered on the event loop, which may be
processed by a blocking call inside another autocommand.

- ChanInfo
- ChanOpen
- TermRequest
- TermResponse

There are some other events that are triggered on the event loop, but
they are mostly triggered by user actions in a UI client, and therefore
not very likely to happen during another autocommand, so leave them
unchanged for now.

src/nvim/api/ui.c

@@ -510,7 +510,7 @@ void nvim_ui_term_event(uint64_t channel_id, String event, Object value, Error *
 
     MAXSIZE_TEMP_DICT(data, 1);
     PUT_C(data, "sequence", value);
-    apply_autocmds_group(EVENT_TERMRESPONSE, NULL, NULL, false, AUGROUP_ALL, NULL, NULL,
+    apply_autocmds_group(EVENT_TERMRESPONSE, NULL, NULL, true, AUGROUP_ALL, NULL, NULL,
                          &DICT_OBJ(data));
   }
 }

src/nvim/channel.c

@@ -897,7 +897,7 @@ static void set_info_event(void **argv)
   tv_dict_add_dict(dict, S_LEN("info"), retval.vval.v_dict);
   tv_dict_set_keys_readonly(dict);
 
-  apply_autocmds(event, NULL, NULL, false, curbuf);
+  apply_autocmds(event, NULL, NULL, true, curbuf);
 
   restore_v_event(dict, &save_v_event);
   arena_mem_free(arena_finish(&arena));

src/nvim/terminal.c

@@ -243,7 +243,7 @@ static void emit_termrequest(void **argv)
   PUT_C(data, "cursor", ARRAY_OBJ(cursor));
 
   buf_T *buf = handle_get_buffer(term->buf_handle);
-  apply_autocmds_group(EVENT_TERMREQUEST, NULL, NULL, false, AUGROUP_ALL, buf, NULL,
+  apply_autocmds_group(EVENT_TERMREQUEST, NULL, NULL, true, AUGROUP_ALL, buf, NULL,
                        &DICT_OBJ(data));
   xfree(sequence);