basalt-26.3: sql/schemachange: TestColumnConversions failed

sql/schemachange.TestColumnConversions [failed](https://mesolite.cluster.engflow.com/invocations/default/c7dd1aa1-f0fb-44b7-8ab3-e0fe3c625b76?testReportRun=2&testReportShard=1&testReportAttempt=1#targets-Ly9wa2cvc3FsL3NjaGVtYWNoYW5nZTpzY2hlbWFjaGFuZ2VfdGVzdA==) on basalt-26.3 @ [1326f194d41c7a5187da0509cee33d331d2229de](https://github.com/cockroachdb/cockroach/commits/1326f194d41c7a5187da0509cee33d331d2229de):

```
github.com/cockroachdb/cockroach/pkg/sql.(*deleteNode).startExec(0xc024c42388, {{0xa3153f8, 0xc02156ea00}, 0xc012e52008, 0xc038432d88})
pkg/sql/delete.go:101 +0x26c
github.com/cockroachdb/cockroach/pkg/sql.startExec({{0xa3153f8?, 0xc02156ea00?}, 0xc012e52008?, 0xc038432d88?}, {0xa35c250, 0xc024c42388})
pkg/sql/plan.go:566 +0x35b
github.com/cockroachdb/cockroach/pkg/sql.(*planNodeToRowSource).Start(0xc025359188, {0xa3153f8, 0xc02156ea00})
pkg/sql/plan_node_to_row_source.go:210 +0x219
github.com/cockroachdb/cockroach/pkg/sql/colflow.(*FlowCoordinator).Start.func1()
pkg/sql/colflow/flow_coordinator.go:113 +0x6b
github.com/cockroachdb/cockroach/pkg/sql/colexecerror.CatchVectorizedRuntimeError(0xc03a1b9ca0)
pkg/sql/colexecerror/error.go:162 +0x79
github.com/cockroachdb/cockroach/pkg/sql/colflow.(*FlowCoordinator).Start(0xc01ad3fe00, {0xa3153f8, 0xc02156ea00})
pkg/sql/colflow/flow_coordinator.go:112 +0xd3
github.com/cockroachdb/cockroach/pkg/sql/execinfra.(*ProcessorBaseNoHelper).Run(0xc01ad3fe00, {0xa3153f8, 0xc02156ea00}, {0xa2df428, 0xc01e7bbb08})
pkg/sql/execinfra/processorsbase.go:776 +0x8d
github.com/cockroachdb/cockroach/pkg/sql/flowinfra.(*FlowBase).Run(0xc018638a08, {0xa3153f8, 0xc02156ea00}, 0x0)
pkg/sql/flowinfra/flow.go:593 +0x767
github.com/cockroachdb/cockroach/pkg/sql/colflow.(*vectorizedFlow).Run(0xc02156e9b0, {0xa3153f8, 0xc02156ea00}, 0x0)
pkg/sql/colflow/vectorized_flow.go:302 +0x37b
github.com/cockroachdb/cockroach/pkg/sql.(*DistSQLPlanner).Run(0xc01805b1e0, {0xa3153f8, 0xc02156ea00}, 0xc01a675380, 0xc015bf68c0, 0xc01d2cc200, 0xc01e7bbb08, 0xc0384333c8, 0xc03a1ba9f0)
pkg/sql/distsql_running.go:1091 +0x1c56
github.com/cockroachdb/cockroach/pkg/sql.(*DistSQLPlanner).PlanAndRun(0xc01805b1e0, {0xa316968, 0xc0216468c0}, 0xc0384333c8, 0xc01a675380, 0xc015bf68c0, {{0xa35c250, 0xc024c42388}, 0x0}, 0xc01e7bbb08, ...)
pkg/sql/distsql_running.go:2408 +0x3b5
github.com/cockroachdb/cockroach/pkg/sql.(*DistSQLPlanner).PlanAndRunAll.func3(0xc038432d88, 0xc01805b1e0, {0xa316968, 0xc0216468c0}, 0xc0384333c8, 0xc01a675380, 0xc01e7bbb08)
pkg/sql/distsql_running.go:2107 +0x19d
github.com/cockroachdb/cockroach/pkg/sql.(*DistSQLPlanner).PlanAndRunAll(0xc01805b1e0, {0xa316968, 0xc0216468c0}, 0xc0384333c8, 0xc01a675380, 0xc038432d88, 0xc01e7bbb08, 0x0)
pkg/sql/distsql_running.go:2110 +0x358
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execWithDistSQLEngine(0xc038432508, {0xa316968, 0xc0216468c0}, 0xc038432d88, 0x2, {0xa3a86d0, 0xc02156e140}, 0x0, 0xc020b12558, 0x80)
pkg/sql/conn_executor_exec.go:3868 +0xa71
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).dispatchToExecutionEngine(0xc038432508, {0xa316968, 0xc0216468c0}, 0xc038432d88, {0xa3a86d0, 0xc02156e140})
pkg/sql/conn_executor_exec.go:3247 +0x27e5
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execStmtInOpenState(0xc038432508, {0xa3153f8, 0xc021291a90}, {{0xa340d20, 0xc0157b2850}, {0x0, 0x0, 0x0}, {0xa11312b, 0xbd}, ...}, ...)
pkg/sql/conn_executor_exec.go:1161 +0x6a76
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execStmt.func2({0xa3153f8, 0xc021291a90})
pkg/sql/conn_executor_exec.go:185 +0x173
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execWithProfiling(0xc038432508, {0xa3153f8, 0xc021291a90}, {0xa340d20, 0xc0157b2850}, 0xc002bb2d88, 0xc01d2c8e98)
pkg/sql/conn_executor_exec.go:4978 +0x977
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execStmt(0xc038432508, {0xa3153f8, 0xc021291a90}, {{0xa340d20, 0xc0157b2850}, {0x0, 0x0, 0x0}, {0xa11312b, 0xbd}, ...}, ...)
pkg/sql/conn_executor_exec.go:184 +0xe67
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execPortal(0xc038432508, {0xa3153f8, 0xc021291a90}, {{0x0, 0x0}, 0xc002bb2d88, {0xc02dca9e30, 0x3, 0x3}, {0x0, ...}, ...}, ...)
pkg/sql/conn_executor_exec.go:335 +0x725
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execCmd.func2(0xc01d2c9960, 0xc038432508, 0xc03a1bdad8, 0xc03a1bdac8, 0xc01d2c9ab0, 0xc01d2c9730, 0xc01d2c9b28, 0xc03a1bdaf8)
pkg/sql/conn_executor.go:2801 +0x1510
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).execCmd(0xc038432508)
pkg/sql/conn_executor.go:2803 +0x13ef
github.com/cockroachdb/cockroach/pkg/sql.(*connExecutor).run(0xc038432508, {0xa316968, 0xc021646280}, 0xc0175f0dc0, 0xc01caef278, 0x0)
pkg/sql/conn_executor.go:2571 +0x405
github.com/cockroachdb/cockroach/pkg/sql.(*InternalExecutor).runWithEx.func2()
pkg/sql/internal.go:257 +0x276
created by github.com/cockroachdb/cockroach/pkg/sql.(*InternalExecutor).runWithEx in goroutine 530626
pkg/sql/internal.go:254 +0x53f
```

Parameters:
- attempt=1
- race=true
- run=2
- shard=1
Help

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

/cc @cockroachlabs/sql-foundations

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Jira issue: CRDB-67729