roachtest: backup-restore/mixed-version 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-restore/mixed-version [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21515165?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_Roachtests_RoachtestNightlyGcePrivateBazel/21515165?buildTab=artifacts#/backup-restore/mixed-version) on master @ [dd7c17488b8195e0faf32209df0cbd5e298423ed](https://github.com/cockroachdb/cockroach/commits/dd7c17488b8195e0faf32209df0cbd5e298423ed):

Failed with:

```
(mixedversion.go:1037).Run: mixed-version test failure while running step 47 (run "verify some backups"): mixed-version: error restoring backup: retries exhausted waiting for job 1210112069919506434 to finish
test artifacts and logs in: /artifacts/backup-restore/mixed-version/run_1
```
Cluster Node to Ip Mapping:
| Node | Public IP | Private IP |
| --- | --- | --- |
| teamcity-21515165-1789365577-11-n5cpu4-0001 | | 10.91.111.240 |
| teamcity-21515165-1789365577-11-n5cpu4-0002 | | 10.91.111.242 |
| teamcity-21515165-1789365577-11-n5cpu4-0003 | | 10.91.111.239 |
| teamcity-21515165-1789365577-11-n5cpu4-0004 | | 10.91.111.241 |
| teamcity-21515165-1789365577-11-n5cpu4-0005 | | 10.91.111.251 |

Parameters:
- arch=amd64
- cloud=gce
- coverageBuild=false
- cpu=4
- diskCount=0
- encrypted=false
- fs=ext4
- localSSD=true
- mvtDeploymentMode=shared-process
- mvtVersions=v26.2.6 → v26.3.1 → v26.4.0-alpha.2-dev-dd7c17488b8195e0faf32209df0cbd5e298423ed (master)
- runtimeAssertionsBuild=true
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-21515165/backup-restore-mixed-version/1789366009267/1789372925382)

See: [Datadog Logs](https://us5.datadoghq.com/logs?query=service%3Aroachtest+%40cluster%3Ateamcity-21515165-1789365577-11-n5cpu4&from_ts=1789366009267&to_ts=1789372925382&live=false&storage=flex_tier)

Same failure on other branches

- #173774 release-26.3.1-rc: roachtest: backup-restore/mixed-version failed [A-disaster-recovery C-test-failure O-roachtest O-robot P-2 T-disaster-recovery branch-release-26.3.1-rc]
- #172161 roachtest: backup-restore/mixed-version failed [A-disaster-recovery B-runtime-assertions-enabled C-test-failure O-roachtest O-robot P-3 T-disaster-recovery branch-release-25.2]
- #170322 roachtest: backup-restore/mixed-version failed [A-disaster-recovery B-runtime-assertions-enabled C-test-failure O-roachtest O-robot P-2 T-disaster-recovery branch-release-26.1]

/cc @cockroachlabs/disaster-recovery

[Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-68382