basalt-26.3: sql/tests: TestSplitAtTableBoundary failed

sql/tests.TestSplitAtTableBoundary [failed](https://mesolite.cluster.engflow.com/invocations/default/22e193ae-13db-4b11-9efe-450a9f57dcbf?testReportRun=3&testReportShard=16&testReportAttempt=1#targets-Ly9wa2cvc3FsL3Rlc3RzOnRlc3RzX3Rlc3Q=) on basalt-26.3 @ [7b7d64a360fe4249bf6409fb266081ab370be355](https://github.com/cockroachdb/cockroach/commits/7b7d64a360fe4249bf6409fb266081ab370be355):

```
=== RUN TestSplitAtTableBoundary
test_log_scope.go:172: test logs captured to: outputs.zip/logTestSplitAtTableBoundary3645920106
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.
```

Parameters:
- attempt=1
- race=true
- run=3
- shard=16
Help

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

Same failure on other branches

- #173682 sql/tests: TestSplitAtTableBoundary failed [A-testing C-bug C-test-failure O-robot T-kv branch-master]

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

Jira issue: CRDB-67916

Start with sql/tests.TestSplitAtTableBoundary and the linked test report, reproducing it with the reported race=true, run=3, and shard=16 parameters. Read test_server_shim.go and the linked internal guide for investigating Go test failures, then inspect the captured logs. Done means identifying the cause, addressing the failure, and confirming the test passes.

Written by the indexing model from the issue text.