feat: add JDK21 version jdk21-2023-08-09-06-56-beta prerelease

[smerle33]

as per jenkins-infra/helpdesk#3709

[dduportal]

Don't forget the Goss tests:

packer-images/goss/goss.yaml

Lines 2 to 21 in f4b1666

	/opt/jdk-8/bin/java -version:
	exit-status: 0
	stderr:
	- 1.8.0_382
	stdout: []
	/opt/jdk-11/bin/java --version:
	exit-status: 0
	stdout:
	- 11.0.20+8
	stderr: []
	/opt/jdk-17/bin/java --version:
	exit-status: 0
	stdout:
	- 17.0.8+7
	stderr: []
	/opt/jdk-19/bin/java --version:
	exit-status: 0
	stdout:
	- 19.0.2+7
	stderr: []

[smerle33]

Don't forget the Goss tests:

packer-images/goss/goss.yaml

Lines 2 to 21 in f4b1666

	/opt/jdk-8/bin/java -version:
	exit-status: 0
	stderr:
	- 1.8.0_382
	stdout: []
	/opt/jdk-11/bin/java --version:
	exit-status: 0
	stdout:
	- 11.0.20+8
	stderr: []
	/opt/jdk-17/bin/java --version:
	exit-status: 0
	stdout:
	- 17.0.8+7
	stderr: []
	/opt/jdk-19/bin/java --version:
	exit-status: 0
	stdout:
	- 19.0.2+7
	stderr: []

planned with the updatecli manifest but I add it now

done

[lemeurherve]

🚀

[dduportal]

LGTM