Argo-cd: switch monkeypatching implementation for license reasons

[ryandawsonuk]

Monkeypatching is being used for one of the tests - https://github.com/argoproj/argo-cd/search?q=bou.ke%2Fmonkey

The implementation is coming from archived git repo and the license says not to use it - https://github.com/bouk/monkey/blob/master/LICENSE.md

This has turned up in a license scan for our project that is using an argocd dependency as it's part of the argocd mod file, even though it's a test dependency.

There is an MIT-licensed alternative available. Could the implementation be switched to that?

[jopit]

/assign @jopit

@alexmt I can look at replacing bou.ke/monkey with github.com/undefinedlabs/go-mpatch (https://github.com/undefinedlabs/go-mpatch) if that package is acceptable