sql: CTAS on crdb_internal.jobs table panics

[chengxiong-ruan]

Describe the problem
CTAS statements querying from crdb_internal.jobs table crashes with error:

runtime error: invalid memory address or nil pointer dereference
(1) attached stack trace
  -- stack trace:
  | runtime.gopanic
  | 	GOROOT/src/runtime/panic.go:884
  | runtime.panicmem
  | 	GOROOT/src/runtime/panic.go:260
  | runtime.sigpanic
  | 	GOROOT/src/runtime/signal_unix.go:835
  | github.com/cockroachdb/cockroach/pkg/sql.(*txnJobsCollection).numToCreate
  | 	github.com/cockroachdb/cockroach/pkg/sql/jobs_collection.go:70
  | github.com/cockroachdb/cockroach/pkg/sql.makeJobsTableRows
  | 	github.com/cockroachdb/cockroach/pkg/sql/crdb_internal.go:1216
  | github.com/cockroachdb/cockroach/pkg/sql.glob..func39
  | 	github.com/cockroachdb/cockroach/pkg/sql/crdb_internal.go:1176
  | github.com/cockroachdb/cockroach/pkg/sql.(*virtualDefEntry).getPlanInfo.func1.1
  | 	github.com/cockroachdb/cockroach/pkg/sql/virtual_schema.go:678
  | github.com/cockroachdb/cockroach/pkg/sql.setupGenerator.func3
  | 	github.com/cockroachdb/cockroach/pkg/sql/virtual_table.go:127
  | github.com/cockroachdb/cockroach/pkg/util/stop.(*Stopper).RunAsyncTaskEx.func2
  | 	github.com/cockroachdb/cockroach/pkg/util/stop/stopper.go:470
  | runtime.goexit
  | 	GOROOT/src/runtime/asm_amd64.s:1594
Wraps: (2) runtime error: invalid memory address or nil pointer dereference
Error types: (1) *withstack.withStack (2) runtime.errorString

To Reproduce
just run CREATE MATERIALIZED VIEW v AS SELECT * FROM [SHOW JOBS]; or CREATE TABLE t AS SELECT * FROM [SHOW JOBS];

Expected behavior
Create materialized view as expected and no panic.

Environment:

• any crdb version after 23.1

Jira issue: CRDB-29258