roachtest: ssh_problem failed

roachtest.ssh_problem [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/19627154?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/19627154?buildTab=artifacts#/ledger/nodes=6/multi-az) on release-25.1.6-rc @ [8277f164925ba5fb24d987ff1af4703d5f084da1](https://github.com/cockroachdb/cockroach/commits/8277f164925ba5fb24d987ff1af4703d5f084da1):

```
test ledger/nodes=6/multi-az failed: (test_runner.go:847).func4: cluster.PutE: put "/go/src/github.com/cockroachdb/cockroach/bin/cockroach.linux-amd64" failed: error persisted after 2 attempts: TRANSIENT_ERROR(ssh_problem): ~ scp -r -C -o StrictHostKeyChecking=no -o ConnectTimeout=10 -i /home/roach/.ssh/id_rsa /go/src/github.com/cockroachdb/cockroach/bin/cockroach.linux-amd64 ubuntu@34.172.167.200:./cockroach
Warning: Permanently added '34.172.167.200' (ECDSA) to the list of known hosts.
System is going down. Unprivileged users are not permitted to log in anymore. For technical details, see pam_nologin(8).
Connection closed by 34.172.167.200 port 22
lost connection: exit status 1 [owner=test-eng]
```

Parameters:
- arch=amd64
- cloud=gce
- coverageBuild=false
- cpu=16
- encrypted=false
- fs=ext4
- localSSD=true
- runtimeAssertionsBuild=false
- ssd=0
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

See: [Grafana](https://go.crdb.dev/roachtest-grafana/teamcity-19627154/ledger-nodes-6-multi-az/-62135596800000/-62135596680000)

Same failure on other branches

- #146027 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.0-rc]
- #145029 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.1.18-rc]
- #144757 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.1.17-rc]
- #144607 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-23.2.24-rc]
- #144541 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.1.5-rc]
- #144529 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.11-rc]
- #144361 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2]
- #143969 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.9-rc]
- #143961 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.1.15-rc]
- #143348 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-23.2.22-rc]

/cc @cockroachdb/test-eng

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*ssh_problem.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-50420