docs: adding restriction to tasklist process diagram view

[marcosgvieira]

Description

It was not clear in the docs that the on Tasklist when trying to check Process Diagrams related to tasks, only diagrams deployed after 8.6 are going to work due to a technical restriction, so I'm adding in the notes.

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support.
• This is already available but undocumented and should be released within a week.
• This on a specific schedule and the assignee will coordinate a release with the DevEx team. (apply hold label or convert to draft PR)
• This is part of a scheduled alpha or minor. (apply alpha or minor label)
• There is no urgency with this change and can be released at any time.

PR Checklist

• My changes are for an already released minor and are in /versioned_docs directory.
• My changes are for the next minor and are in /docs directory (aka /next/).

• My changes require an Engineering review, and I've assigned the Engineering DRI or delegate.
• My changes require a technical writer review, and I've assigned @camunda/tech-writers as a reviewer.

[mesellings]

@marcosgvieira Does this need a TW review?

[marcosgvieira]

@marcosgvieira Does this need a TW review?

thanks @mesellings, Yes, sorry I opened the PR and jumped into a meeting.

Despite it's a super small change, it would be good to have it reviewed.