Fix: Enum-deserialization from _Any-type with ReferenceResolver

[N-Olbert]

Summary of the changes (Less than 80 chars)

• Enums can appear as StringValue in _Any, this was not considered in the ArgumentParser
• Detail 2

Closes #8756 (in this specific format)

[StefanGies99]

Hi @N-Olbert any idea when this is going to be released?

[N-Olbert]

Hi @StefanGies99, unfortunately I cant help with that. This PR hasn’t been triaged for review yet, so I’m not even sure if it will make it into main (though I suspect it will). Probably @michaelstaib has more insight on this and maybe can answer your question.