[GO] fix: correctly use oneOf path parameters

[NickUfer]

Fixes #14028

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[WhoLet2DogsOut]

Hi, may I ask if it would be possible to add this fix into new version of generator? OpenApi generator is not usable for us without OneOf working properly.

[NickUfer]

Well, I don't know man. Since I created this PR a lot of stuff changed again which doesn't work or wasn't properly tested and this change can't be merged because I would have to rewrite everything to this new system which currently outputs reflect.Value+value in a query parameter... and right now rewriting this is the last thing I want to do as it is annoying to me.
Since 2 months I try to use this lib, and all the time I run into the next bug. I just want to finish what I actually build with this lib man

[NickUfer]

I will actually just maintain my own private fork of the version I created this PR for and add more fixes to it if I need them. I will come back in 1 or 2 years to this project and hope it is more stable. Right now there are too many problems and to see that more bugs are added through refactoring or whatever it is... no thanks

[WhoLet2DogsOut]

Totally understand, thank you!