chore(tests): extend ignore_raft_topology_cmd_failing

[timtimb0t]

extending filter to avoid SCT noise due to:
raft_topology - transition_state::left_token_ring errors
Fixes SCT-49

errors like:

2026-02-01 16:04:49.690 <2026-02-01 16:04:48.799>: (DatabaseLogEvent Severity.ERROR) period_type=one-time event_id=a0e81fc5-e4eb-4045-a839-2624d8f6e529: type=RUNTIME_ERROR regex=std::runtime_error line_number=312875 node=longevity-100gb-4h-2026-1-db-node-7e5e7657-2
2026-02-01T16:04:48.799 longevity-100gb-4h-2026-1-db-node-7e5e7657-2  !ERR | scylla[9188]  [shard  0: gms] raft_topology - transition_state::left_token_ring, raft_topology_cmd::command::barrier failed, error std::runtime_error (raft topology: exec_global_command(barrier) failed with seastar::rpc::closed_error (got error from node f6af5c7d-0552-4e4d-b5cf-36995b07b769/10.12.10.30: connection is closed))

are expected when the test initially kills the target node (interrupts bootstrap, removes node from the cluster) and may be ignored by SCT

Testing

local regexp testing

PR pre-checks (self review)

• I added the relevant backport labels
• I didn't leave commented-out/debugging code

Reminders

• Add New configuration option and document them (in sdcm/sct_config.py)
• Add unit tests to cover my changes (under unit-test/ folder)
• Update the Readme/doc folder relevant to this change (if needed)