kotlin-spring: fix exception thrown in enum.forValue

[swurzinger]

This is a suggested fix for #21621 and fixes the forValue() method generated for enum classes to throw the correct exception, IllegalArgumentException in case in invalid enum string is given. Previously NoSuchElementException has been thrown.

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  @dr4ke616 @jimschubert

fixes #21621

[Mattias-Sehlstedt]

Hi,

Could you add one of the terms mentioned in this documentation before your issue reference so that github can better visualize that a PR exists for your issue?

It will add the icon highlighed in red in the image below.

[btpnlsl]

This looks good to me.

[wing328]

https://github.com/OpenAPITools/openapi-generator/actions/runs/16484736455/job/46716135269?pr=21622

please follow step 3 in the checklist to update the samples when you've time

[swurzinger]

I haven't set up the dev environment locally yet, but I'll try to find some time for it over the weekend. If anyone else has it set up already and meanwhile could run + push it to this branch so that I don't have to I'd appreciate that 😊

[btpnlsl]

I was able to run the update for the samples on your branch but I can't push due to permissions:
remote: Permission to swurzinger/openapi-generator.git denied to btpnlsl