next-test: cover the summary, summary_truncate, and plpgsql suites

The suite order predates milestones 10-11; with it stale, a future pin
advance would put todos back on those suites that next-test silently
skips.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01C5Ummi5YEg7pxk5fvRUd3U

Author: claude

cmd/next-test/main.go

@@ -22,6 +22,7 @@ import (
 var suiteOrder = []string{
 	"scan", "split_scanner", "parse", "deparse",
 	"normalize", "normalize_utility", "fingerprint", "split_parser",
+	"summary", "summary_truncate", "plpgsql",
 }
 
 func main() {