[BUG] [REGRESSION] [Java client] bad code generated for uniqueItems enum array

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

Bad java code is generated for a uniqueItems enum array

openapi-generator version

openapi-generator-maven-plugin:6.5.0

OpenAPI declaration file content or url

swagger-bug.zip

Generation Details

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.11.0:compile (default-compile) on project swagger-bug: Compilation failure
[ERROR] /E:/eclipse-workspace-Bamboo/swagger-bug/target/generated-sources/openapi/src/main/java/me/glindholm/bamboo/model/Xyzzy.java:[194,36] incompatible types: me.glindholm.bamboo.model.Xyzzy.ScopesEnum cannot be converted to java.lang.String

for (String _item : getScopes()) {

Steps to reproduce

mvn compile

Start with the attached swagger-bug.zip and reproduce the failure using mvn compile. Inspect the generated Xyzzy.java at the reported loop where ScopesEnum is treated as String; done means the uniqueItems enum array generates compilable Java code without this type mismatch.