[CU-86b4umhm1] Update flink120 to v1.20.3

Author: dnastack-renovate[bot]

gradle/libs.versions.toml

@@ -45,7 +45,7 @@ failsafe = "3.3.2"
 findbugs-jsr305 = "3.0.2"
 flink118 =  { strictly = "1.18.1"}
 flink119 =  { strictly = "1.19.1"}
-flink120 = { strictly = "1.20.0"}
+flink120 = { strictly = "1.20.3"}
 google-libraries-bom = "26.58.0"
 guava = "33.4.6-jre"
 hadoop3 = "3.4.1"