Fix wrong type annotation for sample_query_options in average_fst (closes #987)

Author: rehanxt5

malariagen_data/anoph/fst.py

@@ -363,7 +363,7 @@ def average_fst(
         region: base_params.region,
         cohort1_query: base_params.sample_query,
         cohort2_query: base_params.sample_query,
-        sample_query_options: Optional[base_params.sample_query] = None,
+        sample_query_options: Optional[base_params.sample_query_options] = None,
         sample_sets: Optional[base_params.sample_sets] = None,
         cohort_size: Optional[base_params.cohort_size] = fst_params.cohort_size_default,
         min_cohort_size: Optional[