Pare down Go client 8.6, 8.7, 8.8

[akeller]

Description

Go is not an officially supported client anymore and references to it should be reduced for 8.6+. This PR does exactly that.

When should this change go live?

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

PR Checklist

• My changes are for an upcoming minor release and:
  • are in the /docs directory (version 8.8).
  • are in the /versioned_docs/version-8.7/ directory (version 8.7).
• My changes are for an already released minor and are in a /versioned_docs directory.

• I added a DRI, team, or delegate as a reviewer for technical accuracy and grammar/style:
  • Engineering team review
  • Technical writer review via @camunda/tech-writers unless working with an embedded writer.

[github-actions]

👋 🤖 ✅ Looks like the changes were ported across versions, nice job! 🎉

You can read more about the versioning within our docs in our documentation guidelines.

[akeller]

@aleksander-dytko can you help me look for Go client references? I think most of them are isolated to the APIs & Tools section.

[conceptualshark]

Ran a search through these versions and everything seemed correct on my end! 👍 I only saw the deprecation notices and the content that still remains in the clients section in 8.7 and 8.6.

[akeller]

YEEET