[Kotlin-spring] add springdoc config

[sjoblomj]

This is the Kotlin-spring version of the work @bluenick2k17 did in #12346, related to the issue reported in #12220. As @cachescrubber put it, "this is definitely [needed] to get the springdoc migration feature complete"

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@cachescrubber @jimschubert @dr4ke616 @karismann @Zomzog @andrewemery @4brunu @yutaka0m @wing328

[sjoblomj]

@wing328 I see that version 6.0.0 was supposed to be released yesterday. Any chance of getting this merged, so that Kotlin Spring offers complete springdoc support in the next version? Or is there something I should change or fix in the PR?

All the best, and thank you for your hard unceasing work!

[wing328]

Merged. Thanks for the PR.

[wing328]

Thanks again for the PR, which has been included in the v6.0.0 release: https://twitter.com/oas_generator/status/1529669733934841856