Switched all services to `eclipse-temurin:21-jre`

[demos/kafka/wordcount] / splitter

diff --git a/splitter b/splitter
index e834325..fa9b1d3 160000 (submodule)
--- a/splitter
+++ b/splitter
@@ -1 +1 @@
-Subproject commit e834325a1d41d2b448b7e97b7a491e85f02cd403
+Subproject commit fa9b1d34466c3cc8f8daaaefb926f19a1b7f5251