Cache task is only available in ADO service

[carl-tanner]

Update cache docs so that it is clear that the task is only available in the service, not on-prem product.

[PRMerger7]

@carl-tanner : Thanks for your contribution! The author(s) have been notified to review your proposed change. @damccorm

[ktoliver]

label:"aq-pr-triaged"

[carl-tanner]

Incorrect documentation is referenced in this issue https://github.com/microsoft/azure-pipelines-tasks/issues/13937

[PRMerger12]

@ramiMSFT : Thanks for your contribution! The author(s) have been notified to review your proposed change. @damccorm

[PRMerger8]

@ramiMSFT : Thanks for your contribution! The author(s) have been notified to review your proposed change. @damccorm

[ramiMSFT]

sign-off

[PRMerger16]

@ramiMSFT: I'm sorry - only the author of this article, @damccorm, can sign off on your changes. But we do have an exception process - if you are on the Microsoft content or product team for this product area, you can ask the PR review team to review and merge it by sending mail to the techdocprs alias.

[ramiMSFT]

@ramiMSFT Rami Bououni FTE: I'm sorry - only the author of this article, @damccorm, can sign off on your changes. But we do have an exception process - if you are on the Microsoft content or product team for this product area, you can ask the PR review team to review and merge it by sending mail to the techdocprs alias.

@ktoliver Can you help with this? Thank you

[damccorm]

FWIW, I'm no longer at Microsoft and should probably be removed as the owner here

[Jak-MS]

@ramiMSFT - i'll merge this, but could you follow-up with a change to the author metadata values (in the private repo)? Thanks.