adding OpenShift changes to the upgrade guide and operational guide for self managed

[hamza-m-masood]

Description

Adding OpenShift changes to the upgrade guide and operational guide for self managed.

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.

[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.

[hamza-m-masood]

@conceptualshark this is ready to merge

[conceptualshark]

@hamza-m-masood I've backported your changes here to 8.6 - just confirm that they look good and this can be merged. 👍