add "vacuum" and "analyze" as write hints (they don't write but can only be run on primary)

go.mod

@@ -3,7 +3,7 @@ module gfx.cafe/gfx/pggat
 go 1.19
 
 require (
-	gfx.cafe/ghalliday1/pg3p v0.0.17
+	gfx.cafe/ghalliday1/pg3p v0.0.18
 	gfx.cafe/ghalliday1/pgparser v0.0.9
 	gfx.cafe/util/go/bufpool v0.0.0-20220906091724-3a24b7f40ccf
 	gfx.cafe/util/go/generic v0.0.0-20220917152604-80373e5a2c51

lib/gat/database/query_router/query_router.go

@@ -95,7 +95,9 @@ func (r *QueryRouter) InferRole(query string) (config.ServerRole, error) {
 			lex.KeywordInsert,
 			lex.KeywordDrop,
 			lex.KeywordCreate,
-			lex.KeywordTruncate:
+			lex.KeywordTruncate,
+			lex.KeywordVacuum,
+			lex.KeywordAnalyze:
 			return config.SERVERROLE_PRIMARY, nil
 		case lex.KeywordBegin:
 			depth += 1