* jsonrpcclient: drop Python 3.7 support, add it for 3.9/3.10.
Also: Fixed REQUIRES. jsonrpclient still won't run as the version of
the `click` package in the repos (8.1.3) is too new for this version
of `jsonrpclient` (requires click < 7.x).
Updating to 4.0.3 will require either switching to install from
the wheel (.whl) file provided by the project over PyPi, or having
a working Poetry package in Haiku.
Packaging Poetry and its nearly 30 dependencies is still an on-going
quest, so in the meantime we might want to use that .whl after all.
* jsonrpcclient: update to version 4.0.3.
Had to use the .whl file provided on PyPi, as the tarball depends
on Poetry (and we don't have it on repos).
Tested "ping" example script via aiohttp, against jsonrpcserver.
Got a "pong" as response, so it seems to be working :-)
