[BUG][Java] Nullable on lists that will never be null (with Jackson)

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

Actual: openapi-generator will put @Nullable on lists, while the array is effectively not nullable and being absent.

Expected: no nullable on a list unless explicitly requested via nullable: true or types: [..., null]

openapi-generator version

7.11.0

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: foo API
  version: 0.0.1
paths:
  /foo:
    get:
      responses:
        200:
          description: foo
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Response"
components:
  schemas:
    Response:
      properties:
        names:
          type: array
          items:
            type: string

Steps to reproduce

1. openapi-generator generate -g java --library webclient -i test.yaml

grep -A3 'public class' src/main/java/org/openapitools/client/model/Response.java
public class Response {
  public static final String JSON_PROPERTY_NAMES = "names";
  @javax.annotation.Nullable
  private List<String> names = new ArrayList<>();

3. you can test that it will not be null with this:

	@Test
	public void testDeserializeResponse() throws Exception {
		String requestBody = "{}";
		Response response = new ObjectMapper().readValue(requestBody, Response.class);

		assertEquals(Collections.emptyList(), response.getNames());
	}

Related issues/PRs

Suggest a fix

Start by running openapi-generator generate -g java --library webclient -i test.yaml and inspect the generated Response.java, especially the names field. Use the provided testDeserializeResponse scenario to verify the generated list remains non-null and that @Nullable is absent unless the schema explicitly permits null.