chore(updatecli): add jdk21-preview manifest and adapt check-jdk.sh script

[lemeurherve]

This PR is a follow-up of #521, complement of #535, similar to jenkinsci/docker#1741

Testing done

https://github.com/jenkinsci/docker-agent/actions/runs/6606391106/job/17942546905?pr=536

Corresponding updatecli logs:

########################################################
# BUMP JDK21 PREVIEW VERSION (EA) FOR ALL LINUX IMAGES #
########################################################


SOURCES
=======

getLatestJDK21PreviewVersion
----------------------------
Searching for version matching pattern ".*-ea-.*"
✔ Git tag "jdk-21.0.1+12-ea-beta" found matching pattern ".*-ea-.*" of kind "regex"


CONDITIONS:
===========

checkIfReleaseIsAvailable
-------------------------
The shell 🐚 command "/bin/sh /tmp/updatecli/bin/e178f4342f912570a17f53f2079a8f8a53445ca928f785971065f2d450977844.sh" ran successfully with the following output:
----
OK: all JDK URL for version=21.0.1+12-ea-beta are available.
----
✔ shell condition of type "console/output", passing


TARGETS
========

setJDK21PreviewVersionDockerBake
--------------------------------

**Dry Run enabled**

⚠ - path "variable.JAVA21_PREVIEW_VERSION.default" updated from "21+35" to "21.0.1+12" in file "docker-bake.hcl"


ACTIONS
========

[Dry Run] An action of kind "github/pullrequest" is expected.


###########################################
# BUMP JDK21 VERSION FOR ALL LINUX IMAGES #
###########################################


SOURCES
=======

getLatestJDK21Version
---------------------
Searching for version matching pattern "\\d$"
✔ Git tag "jdk-21+35" found matching pattern "\\d$" of kind "regex"


CONDITIONS:
===========

checkIfReleaseIsAvailable
-------------------------
The shell 🐚 command "/bin/sh /tmp/updatecli/bin/fb063aef0b0daf919e4f1e59666db351f3dc21a3451d2f19630dc86e730839e3.sh" ran successfully with the following output:
----
OK: all JDK URL for version=21+35 are available.
----
✔ shell condition of type "console/output", passing


TARGETS
========

setJDK21Version
---------------

**Dry Run enabled**

✔ - path "variable.JAVA21_VERSION.default" already set to "21_35", from file "docker-bake.hcl", 

LGTM.

Submitter checklist

Preview Give feedback

1. Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
2. Ensure that the pull request title represents the desired changelog entry
3. Please describe what you did
4. Link to relevant issues in GitHub or Jira
5. Link to relevant pull requests, esp. upstream and downstream changes
6. Ensure you have provided tests - that demonstrates feature works or fixes the issue

[dduportal]

Checks looks good:

Run Summary
===========
Pipeline(s) run:
  * Changed:	1
  * Failed:	0
  * Skipped:	2
  * Succeeded:	6
  * Total:	9

=> The changed pipeline is the JDK21 preview 👍