test: skip issue_414 view-chain dependency test on PG 14/15

The dependency/issue_414_function_returns_deferred_view_chain test fails
on PostgreSQL 14/15 due to the pg_get_viewdef() formatting difference
(table-qualified column names) rather than a missing feature. Add it to
skipListPG14_15 alongside the other view tests skipped for this reason.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: tianzhou

testutil/skip_list.go

@@ -26,6 +26,7 @@ var skipListPG14_15 = []string{
 	"create_materialized_view/drop_materialized_view",
 	"dependency/table_to_materialized_view",
 	"dependency/issue_300_function_table_composite_type",
+	"dependency/issue_414_function_returns_deferred_view_chain",
 
 	// Online materialized view index tests - depend on materialized view definitions
 	"online/add_materialized_view_index",