roachtest: ssh_problem failed

roachtest.ssh_problem [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21273336?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21273336?buildTab=artifacts#/acceptance/c2c) on release-25.2.16-rc @ [e6a7db89cfedb398e1b17a8af01a4ee3b96e2e3e](https://github.com/cockroachdb/cockroach/commits/e6a7db89cfedb398e1b17a8af01a4ee3b96e2e3e):

```
test acceptance/c2c failed: (test_runner.go:840).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@34.24.150.229:./cockroach
ssh: connect to host 34.24.150.229 port 22: Connection refused
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-21273336/acceptance-c2c/-62135596800000/-62135596680000)

Same failure on other branches

- #165177 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.15-rc]
- #164800 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.29-rc]
- #164083 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.28-rc]
- #163921 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.6-rc]
- #163918 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1.1-rc]
- #163913 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.14-rc]
- #162299 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.26-rc]
- #161667 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.3.8-rc]
- #161664 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.12-rc]
- #161602 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.4-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-61757

Start with pkg/cmd/roachtest/README.md and the failure site at test_runner.go:840, then compare the acceptance/c2c artifacts and Grafana run with the repeated ssh_problem issues listed here. The report does not specify a code change; done would require identifying and addressing the cause of the SSH connection refusal or documenting why it is an infrastructure flake.

Written by the indexing model from the issue text.