### Apache Airflow version

main (development)

### What happened

Currently when a new task is added to a dag and in the grid view, a user selects the top level of a dag run and then clicks on "Queue up new tasks", the list returned by the confirmation box is always empty. 

It appears that where the list of tasks is expected to be set, [here](https://github.com/apache/airflow/blob/ada91b686508218752fee176d29d63334364a7f2/airflow/api/common/mark_tasks.py#L516), `res` will always be an empty list. 


### What you think should happen instead

The UI should return a list of tasks that will be queued up once the confirmation button is pressed. 

### How to reproduce

Create a dag, trigger the dag, allow it to complete. 

Add a new task to the dag, click on "Queue up new tasks", the list will be empty.

### Operating System

n/a

### Versions of Apache Airflow Providers

2.3.3 and upwards including main. I've not looked at earlier releases. 

### Deployment

Other 3rd-party Helm chart

### Deployment details

_No response_

### Anything else

I have a PR prepared for this issue. 

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

from flask import (
    Response,
    abort,
    before_render_template,
    flash,
    g,
    make_response,
    redirect,
    render_template,
    request,
    send_from_directory,
    session as flask_session,
    url_for,
)
from flask_appbuilder import BaseView, ModelView, expose
from flask_appbuilder.actions import action
from flask_appbuilder.fieldwidgets import Select2Widget
from flask_appbuilder.models.sqla.filters import BaseFilter
from flask_appbuilder.security.decorators import has_access
from flask_appbuilder.urltools import get_order_args, get_page_args, get_page_size_args
from flask_appbuilder.widgets import FormWidget
from flask_babel import lazy_gettext
from jinja2.utils import htmlsafe_json_dumps, pformat  
from markupsafe import Markup, escape
from pendulum.datetime import DateTime
from pendulum.parsing.exceptions import ParserError
from pygments import highlight, lexers
from pygments.formatters import HtmlFormatter
from sqlalchemy import Date, and_, case, desc, func, inspect, union_all
from sqlalchemy.exc import IntegrityError