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/21335253?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyGceBazel/21335253?buildTab=artifacts#/backup/ceph/squid/plain) on release-25.4.10-rc @ [a1989021dd825212349c067edcd07a77597c0781](https://github.com/cockroachdb/cockroach/commits/a1989021dd825212349c067edcd07a77597c0781):

```
(cluster.go:2501).Run: full command output in run_064504.315228410_n4_sudo-snap-install-mi.log: COMMAND_PROBLEM: exit status 1
test artifacts and logs in: /artifacts/backup/ceph/squid/plain/run_1
```

Parameters:
- arch=amd64
- cloud=gce
- coverageBuild=false
- cpu=4
- encrypted=false
- fs=ext4
- localSSD=true
- metamorphicBufferedSender=true
- 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-21335253/backup-ceph-squid-plain/1777704283434/1777704501471)

Same failure on other branches

- #169601 roachtest: backup/ceph/squid/plain failed [B-runtime-assertions-enabled C-test-failure O-roachtest O-robot T-field-eng branch-release-25.2 release-blocker]
- #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-63561