roachtest: ssh_problem failed

**Note:** This build has runtime assertions enabled. If the same failure was hit in a run without assertions enabled, there should be a similar failure without this message. If there isn't one, then this failure is likely due to an assertion violation or (assertion) timeout.

roachtest.ssh_problem [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/19329576?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/19329576?buildTab=artifacts#/rebalance/by-load/replicas/mixed-version) on release-24.1.15-rc @ [5e1c492b9b9649479b7e658090cad480c74a3df6](https://github.com/cockroachdb/cockroach/commits/5e1c492b9b9649479b7e658090cad480c74a3df6):

```
test rebalance/by-load/replicas/mixed-version failed: (mixedversion.go:710).Run: mixed-version test failure while running step 26 (restart node 3 with binary version release-24.1.15-rc): _potential_ SSH flake (``ssh -vvv`` log retained in /artifacts/rebalance/by-load/replicas/mixed-version/run_1/ssh/ssh_092830.931800257_n3_run-start-script.log): TRANSIENT_ERROR(ssh_problem): exit status 255
test artifacts and logs in: /artifacts/rebalance/by-load/replicas/mixed-version/run_1
```

Parameters:
- arch=amd64
- cloud=gce
- coverageBuild=false
- cpu=4
- encrypted=false
- mvtDeploymentMode=system-only
- mvtVersions=v23.2.6 → release-24.1.15-rc
- runtimeAssertionsBuild=true
- 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-19329576/rebalance-by-load-replicas-mixed-version/1743930839894/1743931871442)

Same failure on other branches

- #143348 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-23.2.22-rc]
- #143259 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.1.3-rc]
- #142947 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.1.2-rc]
- #142024 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-23.2.21-rc]
- #141970 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.1.1-rc]
- #141918 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.1.14-rc]
- #141691 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.7-rc]
- #140793 roachtest: ssh_problem failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-release-25.1.0-rc]
- #140365 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.1.12-rc]
- #140343 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.5-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-49184