release-26.2.6-rc: roachtest: ssh_problem failed

roachtest.ssh_problem [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_VectorIndexingRoachtestNightlyGceBazel/21461716?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_VectorIndexingRoachtestNightlyGceBazel/21461716?buildTab=artifacts#/vecindex/random-s/nodes=1/prefix=2) on release-26.2.6-rc @ [c27a8acb37fbc2e0e191decd9b433e27f13b96fb](https://github.com/cockroachdb/cockroach/commits/c27a8acb37fbc2e0e191decd9b433e27f13b96fb):

```
test vecindex/random-s/nodes=1/prefix=2 failed: (test_runner.go:1017).func4: not all nodes booted successfully: timed out after 5m: TRANSIENT_ERROR(ssh_problem): exit status 255 [owner=test-eng]
```

Parameters:
- cloud=gce
- coverageBuild=false
- cpu=4
- diskCount=0
- 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)

Same failure on other branches

- #173320 basalt-26.3: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-basalt-26.3]
- #173321 basalt-26.3: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-basalt-26.3]
- #173249 release-26.3.1-rc: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.3.1-rc]
- #172584 release-26.3.0-rc: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.3.0-rc]
- #172557 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.14-rc]
- #172517 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.22-rc]
- #172515 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1.8-rc]
- #172513 release-26.2.5-rc: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.2.5-rc]
- #172364 release-26.3: roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.3]
- #172363 roachtest: ssh_problem failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]

/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)

Jira issue: CRDB-66644

Start with the TeamCity build log and artifacts for vecindex/random-s/nodes=1/prefix=2, then read the roachtest README at pkg/cmd/roachtest/README.md. Investigate the roachtest.ssh_problem failure and the repeated related issues listed in the report. Done means the underlying failure is addressed and the affected roachtest no longer reports the SSH timeout.

Written by the indexing model from the issue text.