fix: adds missing gitlab to list of supported oidc providers

[NickUfer]

Proposed changes

Adds gitlab to list of supported providers in error message.

Checklist

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[zepatrik]

Nice catch, could you automate that list generation though? That way it will be always up to date.
My suggestion would be to use a pattern similar to this: https://play.golang.org/p/ktNUWwnWb9R

[zepatrik]

Sorry for the crude example but I hope it explains the idea.

[zepatrik]

You can omit the custom type though and just go with strings, that should be fine.
The custom type would only have the benefit to force people to use the case registering function.

[zepatrik]

https://github.com/ory/kratos/blob/master/selfservice/strategy/oidc/provider_config.go#L19-L21 is also out of date, sorry for all the spam.

[NickUfer]

Nice catch, could you automate that list generation though? That way it will be always up to date.
My suggestion would be to use a pattern similar to this: https://play.golang.org/p/ktNUWwnWb9R

Sure. I also thought about refactoring this but my second thought was maybe it's on purpose for simplicity or something.

[zepatrik]

I guess it was because of laziness by @aeneasr 😉

[NickUfer]

hope this is not too over engineered
Okay yeah this is over engineered, I will try your approach 😄

[zepatrik]

Looking good, one other idea I had was to use the python switch approach. You would have to iterate over the map but I think this is nicer 😉

Ah you tried that already, I see.