sql: investigate failure in TestDistSQLReceiverDrainsMeta with shared process mode

With shared process mode the test fails this way:
```
distsql_running_test.go:671:
Error Trace: pkg/sql/distsql_running_test.go:671
Error: Received unexpected error:
waiting for *pgproto3.ReadyForQuery, got &pgproto3.ErrorResponse{Severity:"ERROR", SeverityUnlocalized:"ERROR", Code:"3D000", Message:"database \"test\" does not exist", Detail:"", Hint:"", Position:0, InternalPosition:0, InternalQuery:"", Where:"", SchemaName:"", TableName:"", ColumnName:"", DataTypeName:"", ConstraintName:"", File:"errors.go", Line:209, Routine:"NewUndefinedDatabaseError", UnknownFields:map[uint8]string(nil)}
(1) attached stack trace
-- stack trace:
| github.com/cockroachdb/cockroach/pkg/testutils/pgtest.(*PGTest).Until
| pkg/testutils/pgtest/pgtest.go:196
| github.com/cockroachdb/cockroach/pkg/sql.TestDistSQLReceiverDrainsMeta
| pkg/sql/distsql_running_test.go:670
| testing.tRunner
| GOROOT/src/testing/testing.go:1934
| runtime.goexit
| src/runtime/asm_arm64.s:1268
Wraps: (2) waiting for *pgproto3.ReadyForQuery, got &pgproto3.ErrorResponse{Severity:"ERROR", SeverityUnlocalized:"ERROR", Code:"3D000", Message:"database \"test\" does not exist", Detail:"", Hint:"", Position:0, InternalPosition:0, InternalQuery:"", Where:"", SchemaName:"", TableName:"", ColumnName:"", DataTypeName:"", ConstraintName:"", File:"errors.go", Line:209, Routine:"NewUndefinedDatabaseError", UnknownFields:map[uint8]string(nil)}
Error types: (1) *withstack.withStack (2) *errutil.leafError
Test: TestDistSQLReceiverDrainsMeta
```

Jira issue: CRDB-58394

Epic CRDB-48945