What does this MR do?

This MR adds the ability to edit Knative domain after it has been deployed.

What are the relevant issue numbers?

Closes #56937 (closed)

Successful update

Update failure

To simulate an "Update failure", the following commands can be executed:

Open rails console: bundle exec rails console

In rails console execute the following:

1. cluster = Clusters::Cluster.find <id> Note: <id> can be found in the browser url when navigating to the cluster
2. knative = cluster.application_knative
3. knative.update!(status: 6)

The runner on the specified cluster should now be in the update_errored state, and should display the Retry upgrade button

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides