* [kotlin-spring] Fix no List being used for an array of files using multipart/form-data
* [kotlin-spring] Use Spring's MultipartFile class for incoming Files instead of Spring's Resource class.
* [kotlin-spring] Add test to ensure that return type for files is `org.springframework.core.io.Resource`
* [kotlin-spring] Ensure Array is used for lists of files in generated Api class
* Update samples
* [kotlin-spring] Move conditional usage of MultipartFile to optionalDataType.mustache. Update samples
* update samples
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Co-authored-by: William Cheng <wing328hk@gmail.com>
* [kotlin-server] Bump Kotlin versions to latest
* Run tests on more samples
* Fix typo in workflow definitions
* Update samples
* Bump Gradle to 7.6.4
* Some further tweaks
* Bump Gradle versions
* Fix Gradle version syntax
* [Kotlin Server] Update Ktor to latest version; move config to kts
* Bump gradle version for kotlin server samples
* Replace deprecated gradle API
* Bump gradle to 7.6.4
