ImportError: cannot import name 'soft_unicode' from 'jinja2.utils' with Jinja2 3.0.x

[Jun Omae]

======================================================================
ERROR: test (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: test
Traceback (most recent call last):
  File "/opt/python/3.9.1/lib/python3.9/unittest/loader.py", line 154, in loadTestsFromName
    module = __import__(module_name)
  File "/home/travis/build/edgewall/trac/trac/test.py", line 47, in <module>
    from trac.env import Environment
  File "/home/travis/build/edgewall/trac/trac/env.py", line 52, in <module>
    from trac.web.chrome import Chrome
  File "/home/travis/build/edgewall/trac/trac/web/chrome.py", line 40, in <module>
    from trac.mimeview.api import RenderingContext, get_mimetype
  File "/home/travis/build/edgewall/trac/trac/mimeview/__init__.py", line 14, in <module>
    from trac.mimeview.api import *
  File "/home/travis/build/edgewall/trac/trac/mimeview/api.py", line 70, in <module>
    from trac.resource import Resource
  File "/home/travis/build/edgewall/trac/trac/resource.py", line 21, in <module>
    from trac.util.presentation import classes
  File "/home/travis/build/edgewall/trac/trac/util/presentation.py", line 26, in <module>
    from jinja2.utils import soft_unicode
ImportError: cannot import name 'soft_unicode' from 'jinja2.utils' (/home/travis/virtualenv/python3.9.1/lib/python3.9/site-packages/jinja2/utils.py)

Jinja2 2.11.3 says the following warning when calling soft_unicode() but no warnings when importing it.

$ ~/venv/py39/bin/python
Python 3.9.4 (default, Apr  9 2021, 01:15:05)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import jinja2
>>> jinja2.__version__
'2.11.3'
>>> from jinja2.utils import soft_unicode
>>> soft_unicode('***')
<stdin>:1: DeprecationWarning: 'jinja2.utils.soft_unicode' will be removed in version 3.0. Use 'markupsafe.soft_unicode' instead.
'***'