Panic in server

[hongyunyan]

What did you do?

run the intergration test

What did you expect to see?

pass

What did you see instead?

`=== Command to ticdc(new arch).
--- FAIL: TestRunMain (300.23s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xa900c3a]

goroutine 534 [running]:
testing.tRunner.func1.2({0xb2120c0, 0x1083a260})
/opt/hostedtoolcache/go/1.23.4/x64/src/testing/testing.go:1632 +0x3fc
testing.tRunner.func1()
/opt/hostedtoolcache/go/1.23.4/x64/src/testing/testing.go:1635 +0x6b6
panic({0xb2120c0?, 0x1083a260?})
/opt/hostedtoolcache/go/1.23.4/x64/src/runtime/panic.go:785 +0x132
github.com/pingcap/ticdc/server.(*server).Close(0xc0039524b0, {0xcd87580, 0xc0015b7db0})
/home/runner/work/ticdc/ticdc/server/server.go:303 +0x91a
github.com/pingcap/ticdc/cmd/cdc/server.(*options).run(0xc000e40e70, 0xc0011db808)
/home/runner/work/ticdc/ticdc/cmd/cdc/server/server.go:121 +0x1151
github.com/pingcap/ticdc/cmd/cdc/server.NewCmdServer.func1(0xc0011db808, {0xc00136fd60?, 0x0?, 0xbc2b01a?})
/home/runner/work/ticdc/ticdc/cmd/cdc/server/server.go:230 +0x94
github.com/spf13/cobra.(*Command).execute(0xc0011db808, {0xc00136fae0, 0xa, 0xa})
/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:985 +0x10f4
github.com/spf13/cobra.(*Command).ExecuteC(0xc0011da308)
/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:1117 +0x656
github.com/spf13/cobra.(*Command).Execute(...)
/home/runner/go/pkg/mod/github.com/spf13/[email protected]/command.go:1041
github.com/pingcap/ticdc/cmd/cdc.main()
/home/runner/work/ticdc/ticdc/cmd/cdc/main.go:132 +0x55b
github.com/pingcap/ticdc/cmd/cdc.TestRunMain(0xc003706680?)
/home/runner/work/ticdc/ticdc/cmd/cdc/main_test.go:35 +0x1e5
testing.tRunner(0xc003706680, 0xbf03188)
/opt/hostedtoolcache/go/1.23.4/x64/src/testing/testing.go:1690 +0x227
created by testing.(*T).Run in goroutine 1
/opt/hostedtoolcache/go/1.23.4/x64/src/testing/testing.go:1743 +0x826

LINK:https://github.com/pingcap/ticdc/actions/runs/12980588868/job/36197823600?pr=958

### Versions of the cluster

Upstream TiDB cluster version (execute `SELECT tidb_version();` in a MySQL client):

```console
(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

(paste TiCDC version here)