[BUG][Kotlin] java.lang.IllegalArgumentException: Unexpected char when using non-ascii chars in headers

[Djaler]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
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Description

ApiClient throws an exception when building request with header value that contains non-ascii characters. In our case this is uploaded file name.

openapi-generator version

7.10.0

OpenAPI declaration file content or url

Any spec with header parameters

Generation Details

Generator: kotlin
Library: jvm-okhttp4 (default)

Steps to reproduce

Try to fill header value with non-ascii string.

Related issues/PRs

Similar issue for java client: #9053

Suggest a fix

Okhttp Headers.Builder has a addUnsafeNonAscii method. We should add an option to use this method for specific clients.