Is your feature request related to a problem? Please describe.

When using the spring generator (JavaSpring), the supporting file EnumConverterConfiguration.java is generated without the @Generated annotation. All other generated files (models, API interfaces, delegate interfaces, etc.) are correctly annotated with @Generated via the generatedAnnotation partial. This inconsistency means tools that use @Generated to skip static analysis, formatting, or coverage checks (e.g., Checkstyle, JaCoCo, SonarQube) will incorrectly process EnumConverterConfiguration as hand-written code.

Describe the solution you'd like

Update modules/openapi-generator/src/main/resources/JavaSpring/converter.mustache to include:

1. The jakarta.annotation.Generated import (using {{javaxPackage}}):

   import {{javaxPackage}}.annotation.Generated;

2. The {{>generatedAnnotation}} partial before the class declaration, consistent with pojo.mustache, api.mustache, etc.:

   {{>generatedAnnotation}}
   
   @Configuration(value = "{{configPackage}}.enumConverterConfiguration")
   public class EnumConverterConfiguration {

The resulting generated file would look like:

import jakarta.annotation.Generated;
// ...

@Generated(value = "org.openapitools.codegen.languages.SpringCodegen", ...)
@Configuration(value = "com.example.config.enumConverterConfiguration")
public class EnumConverterConfiguration {
    // ...
}

Describe alternatives you've considered

• Overriding converter.mustache locally in each project — works but requires every consumer to maintain a copy and track upstream changes manually.

Additional context

• The issue affects at least the JavaSpring generator (spring generator name). Other generators with a similar converter.mustache (e.g., java-micronaut-server) may be affected too.
• pojo.mustache, api.mustache, and apiDelegate.mustache all already use {{>generatedAnnotation}} as a reference for the correct pattern.
• generatedAnnotation.mustache (the partial) already exists and handles the hideGenerationTimestamp flag correctly.