New:
* Changed parameter mappings such that unassigned values have non-nan default values. This fixes erroneous evaluation of `llh` as `NaN` in some situations (1574)
* Added support for Python 3.10 (1555)
Fixes:
* Fixed a bug when simulation start time was not transferred when copying a solver instance (1573)
* Fixed a bug which led to incorrect sensitivies for models with multiple assignment rules or rate rules (1584)
Other:
* Update CI and documentation settings (1569, 1527, 1572, 1575, 1579, 1580, 1589, 1581)
* Extend set of validated benchmark models that is checked during CI (1571, 1577)
* Fixed string formatting in derivative checks (1585)
* Added helper methods to save and restore model instance-only settings (1576)