[BUG] [java][restclient] Fix missing javax validation imports with list validation

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

Similar to https://github.com/OpenAPITools/openapi-generator/pull/18332, building a rest client does not include the import statements.

List<@Valid AccountRequest> accountRequest

In the above sample, Valid is not found.

openapi-generator version

7.8.0

Generation Details

Spring Boot 3, Spring Framework 6, openapi generator 7.8.0, java17

{
  "groupId":"com.test",
  "artificactId": "account-client",
  "modelPackage": "com.test.model",
  "apiPackage": "com.test.api",
  "useBeanValidation": "true,
  "useTags": true,
  "hideGenerationTimeStamp": true,
  "dateLibrary": "java8-localdatetime",
  "library": "restclient",
  "useJakartaEe": true
}

Steps to reproduce

When using the openapi generator gradle plugin:

./gradlew build

Related issues/PRs

https://github.com/OpenAPITools/openapi-generator/pull/18332

Suggest a fix

Start by reproducing the generated Spring Boot 3 rest client with the Gradle plugin and the shown configuration, then run ./gradlew build. Compare the missing javax or Jakarta validation imports for List with the related PR 18332. Done means the generated client includes the required validation imports and the build succeeds.