Swagger-core 2.1.8 released!

• refs #3926 - extended repeatable annotations support (#3931)
• refs #3904 - annotations support for @JsonValue types (#3930)
• refs #3011 - fix wrongly ignored operations with empty path (#3929)
• bump jetty version, exclude json-smart (#3918, #3919, #3920). Partial JsonTypeInfo.As.WRAPPER_OBJECT support (#2884, #2862) (#3921)
• fix NPE with @JsonIdentityInfo at class level (#3908)
• guava version in jakarta maven plugin - refs #3840 (#3901)
• transformer plugin deps update refs #3840, refs #3890, refs #3891 (#3899)
• Automation: update maven readme version in release (#3898)
• Fix @JsonUnwrapped does not copy required properties: Resolves #3879 (#3880)