Update `dynesty` API to version 1.1+
In #599 (closed) and #600 (closed) issues where noted between bilby and the new dynesty API. We need to update the API to dynesty to utilise the new version.
In #599 (closed) and #600 (closed) issues where noted between bilby and the new dynesty API. We need to update the API to dynesty to utilise the new version.