pybricks.common.logger: Document freeze fix for saving while disconnected.
This was fixed as part of
Fixes
does not have the control attribute enabled.
### Fixed
+- Fixed brief hub freeze on `pybricks.common.Logger.save()` when not connected
+ to the computer ([support#738]).
- Fixed drive base stall flags being set while not stalled ([support#767]).
- Fixed `Motor.run_target` raising exception for short moves ([support#786]).
+[support#738]: https://github.com/pybricks/support/issues/738
[support#767]: https://github.com/pybricks/support/issues/767
[support#786]: https://github.com/pybricks/support/issues/786
