[scala-akka-http-server] Fix array optional parameter invalid default value

Created by: krrrr38

see https://github.com/OpenAPITools/openapi-generator/issues/10675

• ASIS

> ./mvnw clean install
> java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate \
  -g scala-akka-http-server \
  -i petstore-optional-array-parameter.yaml \
  -o /var/tmp/scala-akka-http-server
> grep findByStatus -A4 /var/tmp/scala-akka-http-server/src/main/scala/org/openapitools/server/api/PetApi.scala
    path("pet" / "findByStatus") {
      get {
        parameters("status".as[String].?("new ListBuffer[String]() ")) { (status) =>
            petService.findPetsByStatus(status = status)
        }

• TOBE

> ./mvnw clean install
> java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate \
  -g scala-akka-http-server \
  -i petstore-optional-array-parameter.yaml \
  -o /var/tmp/scala-akka-http-server
> grep findByStatus -A4 /var/tmp/scala-akka-http-server/src/main/scala/org/openapitools/server/api/PetApi.scala
    path("pet" / "findByStatus") {
      get {
        parameters("status".as[String].?) { (status) =>
            petService.findPetsByStatus(status = status)
        }
> # service also become recieving optional value
> grep findPetsByStatus /var/tmp/scala-akka-http-server/src/main/scala/org/openapitools/server/api/PetApi.scala
            petService.findPetsByStatus(status = status)
  def findPetsByStatus200(responsePetarray: Seq[Pet])(implicit toEntityMarshallerPetarray: ToEntityMarshaller[Seq[Pet]]): Route =
  def findPetsByStatus400: Route =
  def findPetsByStatus(status: Option[String])

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