fix: resolve operator ambiguity in i3 foreign key check

Add explicit int2[] cast to key_cols parameter to resolve "operator
is not unique" error when using the @> operator with pg_catalog
schema qualification.

Fixes #62

Author: NikolayS

sql/i3_non_indexed_fks.sql

@@ -63,7 +63,7 @@ with fk_actions ( code, action ) as (
   join fk_cols_list using (fkoid)
   left join index_list on
     conrelid = indrelid
-    and (indkey::int2[])[0:(array_length(key_cols,1) -1)] operator(pg_catalog.@>) key_cols
+    and (indkey::int2[])[0:(array_length(key_cols,1) -1)] operator(pg_catalog.@>) key_cols::int2[]
 
 ), fk_perfect_match as (
   select fkoid