roachtest: backup/ceph/squid/plain 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.backup/ceph/squid/plain [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21363262?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21363262?buildTab=artifacts#/backup/ceph/squid/plain) on release-25.4.11-rc @ [6383ee79d8d482ecf9f08f35f9b9a0e835deef7d](https://github.com/cockroachdb/cockroach/commits/6383ee79d8d482ecf9f08f35f9b9a0e835deef7d):

```
(cluster.go:2501).Run: full command output in run_064422.657558845_n4_tmpcephInitsh.log: COMMAND_PROBLEM: exit status 1
test artifacts and logs in: /artifacts/backup/ceph/squid/plain/cpu_arch=fips/run_1
```

Parameters:
- arch=fips
- cloud=gce
- coverageBuild=false
- cpu=4
- encrypted=false
- metamorphicLeases=default
- metamorphicWriteBuffering=true
- 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-21363262/backup-ceph-squid-plain/1779950618254/1779950887137)

Same failure on other branches

- #169618 roachtest: backup/ceph/squid/plain failed [C-test-failure O-roachtest O-robot T-field-eng branch-master]
- #169608 roachtest: backup/ceph/squid/plain failed [C-test-failure O-roachtest O-robot T-field-eng branch-release-25.4.10-rc]
- #169601 roachtest: backup/ceph/squid/plain failed [C-test-failure O-roachtest O-robot T-field-eng branch-release-25.2]
- #167089 roachtest: backup/ceph/squid/plain failed [B-runtime-assertions-enabled C-test-failure O-roachtest O-robot T-field-eng branch-release-25.4]
- #166253 roachtest: backup/ceph/squid/plain failed [C-test-failure O-roachtest O-robot T-field-eng branch-release-26.1]

/cc @cockroachdb/field-engineering

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

Jira issue: CRDB-64316