tests: Move Litestar under toxgen

[sentrivana]

Remove hardcoded Litestar entries from tox.ini/tox.jinja and let toxgen handle it.

(the pymongo update was pulled in by rerunning the script)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.54%. Comparing base (7406113) to head (1d4fb72).
Report is 1 commits behind head on master.

✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4197      +/-   ##
==========================================
+ Coverage   79.50%   79.54%   +0.04%     
==========================================
  Files         141      141              
  Lines       15738    15738              
  Branches     2675     2675              
==========================================
+ Hits        12512    12519       +7     
+ Misses       2378     2371       -7     
  Partials      848      848              

see 2 files with indirect coverage changes