[BUG] GH tests fail due to obsolete packages

[bkmartinjr]

The current GH unit tests fail due to using obsolete package versions. See: pallets/jinja#1594

Failure:

======================================================================
ERROR: server.tests.unit (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: server.tests.unit
Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/unittest/loader.py", line 470, in _find_test_path
    package = self._get_module_from_name(name)
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/home/runner/work/single-cell-explorer/single-cell-explorer/server/__init__.py", line 3, in <module>
    from server.common.utils.utils import import_plugins
  File "/home/runner/work/single-cell-explorer/single-cell-explorer/server/common/utils/utils.py", line 11, in <module>
    from flask import json
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/flask/__init__.py", line 14, in <module>
    from jinja2 import escape
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/jinja2/__init__.py", line 12, in <module>
    from .environment import Environment
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/jinja2/environment.py", line [25](https://github.com/chanzuckerberg/single-cell-explorer/runs/5249778612?check_suite_focus=true#step:7:25), in <module>
    from .defaults import BLOCK_END_STRING
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/jinja2/defaults.py", line 3, in <module>
    from .filters import FILTERS as DEFAULT_FILTERS  # noqa: F[40](https://github.com/chanzuckerberg/single-cell-explorer/runs/5249778612?check_suite_focus=true#step:7:40)1
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/jinja2/filters.py", line 13, in <module>
    from markupsafe import soft_unicode
ImportError: cannot import name 'soft_unicode' from 'markupsafe' (/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/site-packages/markupsafe/__init__.py)