Upgrade JDK to 21.0.6+7 (#16990)

Author: jsvd

versions.yml

@@ -7,8 +7,8 @@ logstash-core-plugin-api: 2.1.16
 bundled_jdk:
   # for AdoptOpenJDK/OpenJDK jdk-14.0.1+7.1, the revision is 14.0.1 while the build is 7.1
   vendor: "adoptium"
-  revision: 21.0.3
-  build: 9
+  revision: 21.0.6
+  build: 7
 
 # jruby must reference a *released* version of jruby which can be downloaded from the official download url
 # *and* for which jars artifacts are published for compile-time