Java 17 goes EOL in September 2026 and Jenkins already supports Java 21. So bump the Java version to 21. Signed-off-by: Felix Singer <felixsinger@posteo.net>
Java 17 goes EOL in September 2026 and Jenkins already supports Java 21. So bump the Java version to 21. Signed-off-by: Felix Singer <felixsinger@posteo.net>