Currently Linux has a limit of IGMP memberships of 20. When trying to
add membership to more than that, Linux fails with:
OSError: [Errno 105] No buffer space available
Allowing more memberships should not really be problematic as memory is
allocated dynamically when membership is actually added.
However, there is a protocol limit of how many memberships a host can be
in. The number of memberships needs to fit in a single group report
datagram of 64kB. In total 5459 group records fit in a datagram, but due
to IP header options this might be slightly smaller in practise.
(see https://github.com/home-assistant/core/issues/45957).
Use a limit of 1024, which should be plenty of headroom in both
directions.
Related to: https://github.com/home-assistant/core/issues/45957
