fix(longevity_test): Set ignore 'raft topology connection close' error globally

[aleksbykov]

Error: 'raft_topology - topology change coordinator fiber got error (connection is closed))' Could appeared in different moment when node/nodes are being restarted. As described in issue: scylladb/scylladb#20950 in comment: https://github.com/scylladb/scylladb/issues/20950#issuecomment-2411387784

the error message could appeared while we have race between raft and gossip. we can ignore this issue while issue will not be fixed on scylla side, gossip mode will be removed from scylla.

Testing

• Job https://argus.scylladb.com/tests/scylla-cluster-tests/840673cf-ce9f-4022-95df-a3ad0b7d1d2d currently failed by another issue

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)

[fruch]

@aleksbykov you added this inside if self.validate_large_collections: clause

so it's not exactly globally as the title says, it would work only if a case has validation for large collection enabled

[vponomaryov]

Looks like it broke one of our integration tests:

• https://github.com/scylladb/scylla-cluster-tests/issues/10676