net/py-python-socks: Drop devel/py-anyio3 as dependency

devel/py-anyio3 is an optional dependency. Now that there is devel/py-anyio
available, many ports started depending on devel/py-anyio. Now finance/electrum
is broken because somewhere down the dependency chain devel/py-anyio and
devel/py-anyio3 get pulled in together which obviously conflict on eachother.

Since anyio is an optional dependency, drop it in order to fix
finance/electrum. Once net/py-python-socks supports anyio version 4.x
it can be added again.