The `_remaining_nodes` attribute of the data center information was not
initialized correctly. The parameter was passed by value to the
initialization function instead of by reference or pointer.
As a result, `_remaining_nodes` was left initialized to zero, causing an
underflow when decrementing its value.
This bug did not significantly impact behavior because other safeguards,
such as capping the maximum voters per data center by the total number
of nodes, masked the issue. However, it could lead to inefficiencies, as
the remaining nodes check would not trigger correctly.
Fixes: scylladb/scylladb#23702
No backport: The bug is only present in the master branch, so no backport
is required.
Closesscylladb/scylladb#23704