sql/tests: TestSplitAtTableBoundary failed

sql/tests.TestSplitAtTableBoundary [failed](https://mesolite.cluster.engflow.com/invocations/default/bf1b0237-f3fe-418b-b188-4352b5cbd52e?testReportRun=1&testReportShard=16&testReportAttempt=1#targets-Ly9wa2cvc3FsL3Rlc3RzOnRlc3RzX3Rlc3Q=) on master @ [dd7c17488b8195e0faf32209df0cbd5e298423ed](https://github.com/cockroachdb/cockroach/commits/dd7c17488b8195e0faf32209df0cbd5e298423ed):

```
=== RUN TestSplitAtTableBoundary
test_log_scope.go:172: test logs captured to: outputs.zip/logTestSplitAtTableBoundary2659758962
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.
table_split_test.go:53: condition failed to evaluate within 3m45s: from table_split_test.go:60: expected range start key /Tenant/10/Table/116; got /Tenant/10/Table/84

goroutine dump: /mnt/engflow/worker/work/1/exec/bazel-out/k8-fastbuild/testlogs/pkg/sql/tests/tests_test/shard_16_of_16_run_1_of_3/test.outputs/goroutine_dump_1621478001.txt
panic.go:694: -- test log scope end --
test logs left over in: outputs.zip/logTestSplitAtTableBoundary2659758962
--- FAIL: TestSplitAtTableBoundary (2607.65s)
```

Parameters:
- attempt=1
- race=true
- run=1
- 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

- #175422 basalt-26.3.2-rc-20260913: sql/tests: TestSplitAtTableBoundary failed [OOM] [C-test-failure O-robot T-sql-queries branch-basalt-26.3.2-rc-20260913]
- #174997 basalt-26.3.2-rc-20260908: sql/tests: TestSplitAtTableBoundary failed [OOM] [C-test-failure O-robot T-sql-queries branch-basalt-26.3.2-rc-20260908]
- #174915 basalt-26.3.2-rc-20260908: sql/tests: TestSplitAtTableBoundary failed [C-test-failure O-robot T-sql-queries branch-basalt-26.3.2-rc-20260908]
- #174818 release-26.3: sql/tests: TestSplitAtTableBoundary failed [C-test-failure O-robot T-sql-queries branch-release-26.3]
- #174815 release-26.2: sql/tests: TestSplitAtTableBoundary failed [OOM] [C-test-failure O-robot T-sql-queries branch-release-26.2]
- #174697 basalt-26.3: sql/tests: TestSplitAtTableBoundary failed [C-test-failure O-robot T-sql-queries branch-basalt-26.3]

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

Jira issue: CRDB-68386

Start with sql/tests/table_split_test.go, especially the condition at line 60, and inspect the linked test report and captured logs for TestSplitAtTableBoundary. Reproduce the failure with the reported race-enabled test configuration, then identify and correct the cause so the expected range start key is observed reliably and the test passes.

Written by the indexing model from the issue text.