Small optimization in `find_annotated_strategy`

[Victorien]

Currently working on the Pydantic hypothesis plugin, figured the following could be optimized a bit:

hypothesis/hypothesis-python/src/hypothesis/strategies/_internal/types.py

Lines 346 to 350 in c579480

 for constraint in _get_constraints(metadata): 
     if convert := get_constraints_filter_map().get(type(constraint)): 
         filter_conditions.append(convert(constraint)) 
     else: 
         unsupported.append(constraint) 

By building the filter map once before the for loop. If you agree, PR ready to be pushed.

[Zac Hatfield-Dodds]

Yes please!