We are supposed to be loading the most recent RPC compression dictionary
on startup, but we forgot to port the relevant piece of logic during
the source-available port. This causes a restarted node not to use the
dictionary for RPC compression until the next dictionary update.
Fix that.
Fixesscylladb/scylladb#22738
This is more of a bugfix than an improvement, so it should be backported to 2025.1.
Closesscylladb/scylladb#22739
* github.com:scylladb/scylladb:
test_rpc_compression.py: test the dictionaries are loaded on startup
raft/group0_state_machine: load current RPC compression dict on startup