roachtest: ssh_problem failed

roachtest.ssh_problem [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21499468?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21499468?buildTab=artifacts#/jepsen/monotonic/subcritical-skews) on release-25.2.24-rc @ [92c7311721160180bed1228023264f6df947fc1e](https://github.com/cockroachdb/cockroach/commits/92c7311721160180bed1228023264f6df947fc1e):

```
test jepsen/monotonic/subcritical-skews failed: (test_runner.go:856).func4: cluster.PutE: put "/go/src/github.com/cockroachdb/cockroach/bin/cockroach.linux-amd64" failed: 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@10.91.99.112:./cockroach
ssh: connect to host 10.91.99.112 port 22: Connection timed out
lost connection: exit status 1 [owner=test-eng]
```

Parameters:
- arch=amd64
- cloud=gce
- coverageBuild=false
- cpu=4
- diskCount=0
- encrypted=false
- fs=ext4
- localSSD=true
- runtimeAssertionsBuild=false
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-21499468/jepsen-monotonic-subcritical-skews/-62135596800000/-62135596680000)

Same failure on other branches

- #174690 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.17-rc]
- #173564 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.15-rc]
- #173555 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.23-rc]

/cc @cockroachlabs/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)

Start with pkg/cmd/roachtest/README.md and the failure at test_runner.go:856, then inspect the linked TeamCity log and artifacts for the GCE SSH timeout. Compare the repeated failures in issues #174690, #173564, and #173555. Done means identifying the cause of the ssh_problem failure and documenting or implementing a verified fix for this roachtest path.

Written by the indexing model from the issue text.