fix: update to UDFContext for trans_numeric_udf function (#119)

Author: nehanene15

ibis_bigquery/datatypes.py

@@ -111,6 +111,6 @@ def trans_numeric(t, context):
     return "NUMERIC"
 
 
-@ibis_type_to_bigquery_type.register(dt.Decimal, TypeTranslationContext)
+@ibis_type_to_bigquery_type.register(dt.Decimal, UDFContext)
 def trans_numeric_udf(t, context):
     raise TypeError("Decimal types are not supported in BigQuery UDFs")