Refs #26285 -- Removed postgresql's unused DatabaseOperations.fulltext_search_sql().

Should have been removed in 51398323.

django/db/backends/postgresql/operations.py

@@ -255,9 +255,3 @@ class DatabaseOperations(BaseDatabaseOperations):
             rhs_sql, rhs_params = rhs
             return "(interval '1 day' * (%s - %s))" % (lhs_sql, rhs_sql), lhs_params + rhs_params
         return super().subtract_temporals(internal_type, lhs, rhs)
-
-    def fulltext_search_sql(self, field_name):
-        raise NotImplementedError(
-            "Add 'django.contrib.postgres' to settings.INSTALLED_APPS to use "
-            "the search operator."
-        )