[Java][Spring] Fix #14398 springboot 3 schema required

[parenko]

Fix for #14398

Schema#required is deprecated since 2.2.5 and replaced by requiredMode.

OAS3 required parameter is of type boolean and defaults to false thus I used Schema.RequiredMode.NOT_REQUIRED when required is false.

I have checked following samples for compilation, such that min >= 2.2.5 swagger-annotations library is used.

• samples/openapi3/client/petstore/spring-cloud-3/
• samples/openapi3/client/petstore/spring-cloud-async/
• samples/openapi3/client/petstore/spring-cloud-date-time/
• samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/
• samples/openapi3/client/petstore/spring-cloud-spring-pageable/
• samples/openapi3/client/petstore/spring-cloud/
• samples/openapi3/client/petstore/spring-stubs-skip-default-interface/
• samples/openapi3/client/petstore/spring-stubs/
• samples/openapi3/server/petstore/spring-boot-oneof/
• samples/openapi3/server/petstore/spring-boot-springdoc/
• samples/openapi3/server/petstore/springboot-3/
• samples/openapi3/server/petstore/springboot-beanvalidation-no-nullable/
• samples/openapi3/server/petstore/springboot-delegate/
• samples/openapi3/server/petstore/springboot-implicitHeaders/
• samples/openapi3/server/petstore/springboot-reactive/
• samples/openapi3/server/petstore/springboot-useoptional/
• samples/openapi3/server/petstore/springboot/
• samples/server/petstore/java-camel/
• samples/server/petstore/java-micronaut-server/pom.xml
• samples/server/petstore/java-micronaut-server/
• samples/server/petstore/spring-boot-defaultInterface-unhandledException/
• samples/server/petstore/spring-boot-nullable-set/
• samples/server/petstore/springboot-virtualan/

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[parenko]

Notify technical committee:

Language	Member
Java	@bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04) @lwlee2608 (2019/10)
Java Spring	@cachescrubber (2022/02) @welshm (2022/02) @MelleD (2022/02) @atextor (2022/02) @manedev79 (2022/02) @javisst (2022/02) @borsch (2022/02) @banlevente (2022/02) @Zomzog (2022/09)
Kotlin	@jimschubert (2017/09) ❤️, @dr4ke616 (2018/08) @karismann (2019/03) @Zomzog (2019/04) @andrewemery (2019/10) @4brunu (2019/11) @yutaka0m (2020/03)