BIGTOP-3874. Bump Flink to 1.15.3 (#1057)

diff --git a/bigtop.bom b/bigtop.bom
index 2c41600..949c78f 100644
--- a/bigtop.bom
+++ b/bigtop.bom
@@ -223,7 +223,7 @@
     'flink' {
       name    = 'flink'
       relNotes = 'Apache Flink'
-      version { base = '1.15.0'; pkg = base; release = 1 }
+      version { base = '1.15.3'; pkg = base; release = 1 }
       tarball { destination = "$name-${version.base}.tar.gz"
                 source      = "$name-${version.base}-src.tgz" }
       url     { download_path = "/$name/$name-${version.base}"