[BUG][scala-play-server] additionalProperties settings is not working and generated code is having compilation issue

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?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Generated source having compilation issue for generator 'scala-play-server'.

1. additionalProperties - does not have any type added by default unless we specify additionalProperties=true
2. Attribute present before additionalProperties does not ends with comma(,) at the end which leads to compilation error.

package model

import play.api.libs.json._

/**
  * A category for a pet
  * @param additionalProperties Any additional properties this model may have.
  */
@javax.annotation.Generated(value = Array("org.openapitools.codegen.languages.ScalaPlayFrameworkServerCodegen"))
case class Category(
  id: Option[Long],
  name: Option[String]
  additionalProperties:
)

openapi-generator version

Latest master branch code

OpenAPI declaration file content or url

Generation Details

Navigate to root folder of this project and issue below command after building.

java -jar ./modules/openapi-generator-cli/target/openapi-generator-cli.jar generate --generator-name="scala-play-server" --input-spec=modules/openapi-generator/src/test/resources/3_0/petstore.yaml --output=samples/server/petstore/scala-play-server

Steps to reproduce

1. Clone master branch
2. Open terminal in mac
3. issue command ./mvnw
4. Once build is successful, try issue below command to regenerate samples - bin/generate-samples.sh
5. Notice the samples present samples/server/petstore/scala-play-server/app/model/ and we can see above mentioned two issues.

Expected output:

package model

import play.api.libs.json._

/**
  * A category for a pet
  */

case class Category(
  id: Option[Long],
  name: Option[String]
)

object Category {
  implicit lazy val categoryJsonFormat: Format[Category] = Json.format[Category]
}

Related issues/PRs

Suggest a fix

Build the project with ./mvnw, then reproduce with the scala-play-server command using modules/openapi-generator/src/test/resources/3_0/petstore.yaml. Inspect the generated model under samples/server/petstore/scala-play-server/app/model/, especially Category.scala, and compare it with the expected output in the issue. Done means the generated Scala source compiles and the additionalProperties and comma handling match the expected model.