Update vendored JDK for logstash artifacts

[donoghuc]

The weekly java version checks in CI are failing https://buildkite.com/elastic/logstash-jdk-availability-check-pipeline/builds/53

Found new jdk version. Please update version.yml to 21.0.7 build 6

Update the version

logstash/versions.yml

Lines 7 to 11 in d24675a

	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: 21.0.6
	build: 7

in appropriate logstash branches.