False positive diff for array with maxItems fix

[DrSatyr]

fixes #784

[Copilot]

Pull Request Overview

This PR addresses false positive diffs for array maxItems (and similarly for minItems) by replacing reference equality checks with proper object equality checks.

• Replace "oldValue == newValue" with "Objects.equals(oldValue, newValue)" in both ChangedMinItems.java and ChangedMaxItems.java.
• Add the required import for java.util.Objects to support the new equality check.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
core/src/main/java/org/openapitools/openapidiff/core/model/schema/ChangedMinItems.java	Uses Objects.equals for value comparison, reducing false positives.
core/src/main/java/org/openapitools/openapidiff/core/model/schema/ChangedMaxItems.java	Uses Objects.equals for value comparison, ensuring consistency with minItems logic.