Scheduler /history endpoint throws 500 Server Error

[adblair]

Problem

The /history endpoint in the scheduler web UI fails with a 500 error.

Steps to reproduce

Using Python 3.13:

> pip install 'luigi==3.8.0' 'sqlalchemy<1.4'
...

> cat << EOF > luigi.cfg
[scheduler]
record_task_history = True

[task_history]
db_connection = sqlite:///history.sqlite
EOF

> luigid
...

Then visit http://localhost:8082/history

Expected behaviour

Task history UI is shown.

Actual behaviour

"500: Internal Server Error" is shown.

Logs from luigid:

2026-04-08 15:22:19,391 tornado.application[87851] ERROR: Uncaught exception GET /history (::1)
HTTPServerRequest(protocol='http', host='localhost:8082', method='GET', uri='/history', version='HTTP/1.1', remote_ip='::1')
Traceback (most recent call last):
  File "/Users/arthurb/.virtualenvs/temp/lib/python3.13/site-packages/tornado/web.py", line 1878, in _execute
    result = method(*self.path_args, **self.path_kwargs)
  File "/Users/arthurb/.virtualenvs/temp/lib/python3.13/site-packages/luigi/server.py", line 236, in get
    self.render("recent.html", tasks=tasks)
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/arthurb/.virtualenvs/temp/lib/python3.13/site-packages/tornado/web.py", line 1025, in render
    html = self.render_string(template_name, **kwargs)
  File "/Users/arthurb/.virtualenvs/temp/lib/python3.13/site-packages/tornado/web.py", line 1157, in render_string
    template_path = self.get_template_path()
  File "/Users/arthurb/.virtualenvs/temp/lib/python3.13/site-packages/luigi/server.py", line 160, in get_template_path
    return importlib.resources.files("templates").name
           ^^^^^^^^^^^^^^^^^^^
AttributeError: module 'importlib' has no attribute 'resources'
2026-04-08 15:22:19,397 tornado.access[87851] ERROR: 500 GET /history (::1) 13.44ms

Notes

It looks like the relevant change was fc62c36, so this affects 3.7.3+. Should be an easy fix.