Remove explicit disabling of buffer recycling in non-blocking Jackson parsing

[sdeleuze]

As pointed out in this comment, Jackson 2.10 will support buffer recycling for non-blocking parsing. Since it is disabled since Jackson 2.9.7, the purpose of this issue is to remove JsonFactory.Feature.USE_THREAD_LOCAL_FOR_BUFFER_RECYCLING explicit disabling and raise the minimum requirement to Jackson 2.9.7 for Spring Framework 5.2.