EL-1214 UAT Main shared deploy host

[willc-work]

Jira ticket

using a shared host for main on UAT so we can watch what happens when we send traffic from one to the other.
We can set the weight using the kubectl apply command directly in the namespaces (alternative is to update both of the values files).

Guidance to review

Checklist

Before you ask people to review this PR:

• Tests and rubocop should be passing
• Branch is generally up to date with main Github - definitely no conflicts
• No unnecessary whitespace changes. These make diffs harder to read and conflicts more likely.
• PR description says what changed and why, with a link to the JIRA story.
• Diff has been checked for unexpected changes being included.
• Commit messages say why the change was made.

[patrick-laa]

Could we test this before merge by changing the branch deploy host to be identical in both namespaces?