cync_lan (Home Assistant custom_component) v2.11.0

Requires cync-lan 0.11.0. No behaviour changes here - this is the
integration side of a library change that makes it safe to install cync_lan
and cync_ble together.

The library's cloud client used to be a process-wide singleton, so
CyncCloudAPI() anywhere in Home Assistant returned whichever integration
built one first, along with its token and its config directory. That is
invisible with one integration installed and quietly wrong with two: the
second one authenticated as the first one's account, wrote to the first one's
directory, and reported the resulting token failure to its own user as "could
not reach the Cync cloud API."

This integration genuinely does want one client per process - the firmware
sensor reads what the server's periodic check captured - so both call sites
now ask for it by name via CyncCloudAPI.shared() instead of relying on
construction to do it silently. The version floor is a hard requirement
rather than a preference: shared() does not exist in 0.10.4, so an install
that somehow kept the older library would fail at the call rather than
misbehave.

Nothing to do on upgrade, and nothing changes about how this integration
behaves on its own.