According to https://ports.macports.org/port/libde265/details/ we had successful builds of this port on all OS versions.
Your log contains nine attempts to install libde265. The first one failed due to the problem described at ProblemHotlist#clts16. The other eight attempts were continuations of that first attempt without cleaning and may have failed because the first attempt's configure phase made incorrect determinations. For example, your log says:
checking for std::move... no
but on my macOS 12 machine I get:
checking for std::move... yes
As it says at ProblemHotlist#clts16 and at https://guide.macports.org/#project.tickets, please clean the affected port (e.g. sudo port clean libde265) and then try again. If that still fails, please attach the new main.log file.
