L1TopoInterfaces: remove thread_local from AlgFactory
The AlgFactory was wrongly declared as thread_local. It is filled
during initialize and usually not used afterwards. But if another
thread happens to access it, defining it as static thread_local will
result in a new (empty!) instance being created.
For the moment just mark it as ATLAS_THREAD_SAFE but this needs
further refactoring to ensure nobody accidentally modifies the factory
during execution.
Relates to ATR-25362.
Edited by Frank Winklmeier