[hotfix] upgrade v3.0 branch testing flink version to 1.19.1

Author: reswqa

.github/workflows/weekly.yml

@@ -36,7 +36,7 @@ jobs:
           flink: 1.20-SNAPSHOT,
           branch: main
         }, {
-          flink: 1.19.0,
+          flink: 1.19.1,
           branch: v3.0
         }, {
           flink: 1.20.0,