The spawn selection may actually be farther than 32 blocks,
so we need a larger load radius to prevent a deadlock on startup.
Additionally, re-insert thread checks for sync loads that were
previously in 1.20.
This field is covered by the entity tracker optimisations in Paper,
but currently was not properly maintained - resulting in memory leaks.
Fixes https://github.com/PaperMC/Folia/issues/283
Most significant changes are to portal/teleport logic, there may
be some bugs there. Not really concerned about the passenger
teleport, as Folia had already added support for that.
Not sure how the spark changes are going to work.