Use Jackson 3 for JSON processing

[wilkinsona]

[wilkinsona]

This will have to wait until the situation with jackson-annotations has been addressed. Right now, a build of REST Docs that uses Jackson 3 does not work with Spring Boot 4.0 that's still using Jackson 2:

java.lang.NoSuchFieldError: Class com.fasterxml.jackson.annotation.JsonFormat$Shape does not have member field 'com.fasterxml.jackson.annotation.JsonFormat$Shape POJO'
	at tools.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:399)
	at tools.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:361)
	at tools.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:265)
	at tools.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
	at tools.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:158)
	at tools.jackson.databind.DeserializationContext.findNonContextualValueDeserializer(DeserializationContext.java:732)
	at tools.jackson.databind.deser.jdk.UntypedObjectDeserializer._findCustomDeser(UntypedObjectDeserializer.java:179)
	at tools.jackson.databind.deser.jdk.UntypedObjectDeserializer.resolve(UntypedObjectDeserializer.java:152)
	at tools.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:294)
	at tools.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
	at tools.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:158)
	at tools.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:741)
	at tools.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:2871)
	at tools.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2689)
	at tools.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1705)