Convert maintained JAX-RS samples to JUnit 5 (#24173) #3202

Job	Run time
Gradle tests (samples/client/petstore/java/jersey2-java8)	1m 21s
Gradle tests (samples/client/petstore/java/okhttp-gson)	1m 23s
Gradle tests (samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8)	1m 15s
Gradle tests (samples/client/petstore/java/okhttp-gson-group-parameter)	1m 21s
Gradle tests (samples/client/petstore/java/native)	1m 31s
Gradle tests (samples/openapi3/client/petstore/java/jersey2-java8)	1m 28s
Gradle tests (samples/client/petstore/java/webclient-swagger2)	1m 25s
Gradle tests (samples/client/petstore/java/jersey2-java8-localdatetime)	1m 23s
Gradle tests (samples/client/petstore/java/native-jakarta)	1m 7s
Gradle tests (samples/openapi3/client/petstore/java/jersey2-java8-special-characters)	1m 28s
	13m 42s

Provide feedback