Daniel Wischolek

scala-sttp: fix for issue 15785 api returns unit.

3

### PR checklist - [x] Read the [contribution guidelines](https://github.com/openapitools/openapi-generator/blob/master/CONTRIBUTING.md). - [x] Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how...

scala-sttp4: fix for issue 15785 api returns unit.

2

### PR checklist - [x] Read the [contribution guidelines](https://github.com/openapitools/openapi-generator/blob/master/CONTRIBUTING.md). - [x] Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how...