release-26.3.1-rc: pkg/cloud/userfile/filetable/filetabletest/filetabletest_test: TestReadWriteFile failed

pkg/cloud/userfile/filetable/filetabletest/filetabletest_test.TestReadWriteFile [failed](https://mesolite.cluster.engflow.com/invocations/default/71f84fdd-3a75-490f-97f1-b6219a336c8a?testReportRun=3&testReportShard=1&testReportAttempt=1#targets-Ly9wa2cvY2xvdWQvdXNlcmZpbGUvZmlsZXRhYmxlL2ZpbGV0YWJsZXRlc3Q6ZmlsZXRhYmxldGVzdF90ZXN0) on release-26.3.1-rc @ [2717d90119450ebfa34efd9bc1d607349924beac](https://github.com/cockroachdb/cockroach/commits/2717d90119450ebfa34efd9bc1d607349924beac):

```
=== RUN TestReadWriteFile
test_log_scope.go:172: test logs captured to: outputs.zip/logTestReadWriteFile939753386
test_log_scope.go:82: use -show-logs to present logs inline
test_server_shim.go:168: automatically injected an external process virtual cluster under test; see comment at top of test_server_shim.go for details.
=== RUN TestReadWriteFile/write-delete-write
```

Parameters:
- attempt=1
- race=true
- run=3
- shard=1
Help

See also: [How To Investigate a Go Test Failure \(internal\)](https://cockroachlabs.atlassian.net/l/c/HgfXfJgM)

Same failure on other branches

- #172788 release-26.3.0-rc: pkg/cloud/userfile/filetable/filetabletest/filetabletest_test: TestReadWriteFile failed [A-disaster-recovery C-test-failure O-robot P-3 T-disaster-recovery branch-release-26.3.0-rc]
- #172576 pkg/cloud/userfile/filetable/filetabletest/filetabletest_test: TestReadWriteFile failed [A-disaster-recovery C-test-failure O-robot P-3 T-disaster-recovery branch-master]

/cc @cockroachlabs/disaster-recovery

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Jira issue: CRDB-66571

Start with pkg/cloud/userfile/filetable/filetabletest/filetabletest_test.TestReadWriteFile, focusing on the write-delete-write subtest and the captured test logs from the linked failure report. Reproduce the failure with the reported race setting and inspect the referenced test-server shim context; done means identifying and fixing the cause so the test passes on the affected release branch.

Written by the indexing model from the issue text.