[FIX JENKINS-47569] Finalize js-builder & js-extensions post-HPI

[kzantow]

Description

See JENKINS-47569.

Submitter checklist

• Link to JIRA ticket in description, if appropriate.
• Change is code complete and matches issue description
• Appropriate unit or acceptance tests or explanation to why this change has no tests
• Reviewer's manual test instructions provided in PR description. See Reviewer's first task below.

Reviewer checklist

• Run the changes and verified the change matches the issue description
• Reviewed the code
• Verified that the appropriate tests have been written or valid explanation given

[michaelneale]

ping @sophistifunk mind givin this a spin at your leisure?

@kzantow is the executor plugin also published in non snapshot form (just while we are talking finalising)

[michaelneale]

is #1505 really needed to finalize?

[kzantow]

@michaelneale yes, #1505 is required, this one first. I can't publish the executor plugin until this is released in beta, really.

[michaelneale]

if this passes I guess it is ok - not really code to review 👍🏻

[scherler]

looks as a version dumb