[Bug]: ut 'TestReadDirSymlink' failed in ci test.

[Ariznawlll]

Is there an existing issue for the same bug?

• I have checked the existing issues.

Branch Name

Ariznawlll

Commit ID

add_parquet_case

Other Environment Information

- Hardware parameters:
- OS type:
- Others:

Actual Behavior

url: https://github.com/matrixorigin/matrixone/actions/runs/21383868217/job/61556288484?pr=23597

[OUTPUTS]:
=== RUN   TestReadDirSymlink
    external_test.go:392: Created temp directory: /tmp/66676782
    external_test.go:401: Root path: /tmp/66676782 (no symlink resolution needed)
    external_test.go:451: Created directory structure: /tmp/66676782/a/b/c
    external_test.go:457: Created test file: /tmp/66676782/a/b/c/foo
    external_test.go:464: Created symlink: /tmp/66676782/a/b/d -> /tmp/66676782/a/b/c
    external_test.go:432: notify: notify.Create: "/tmp/66676782/a"
    external_test.go:482: Symlink verification: /tmp/66676782/a/b/d resolves to /tmp/66676782/a/b/c (expected: /tmp/66676782/a/b/c)
    external_test.go:486: Testing ReadDir with path through symlink: /tmp/66676782/a/b/d/foo
    external_test.go:511: ReadDir succeeded on attempt 1, found 1 file(s)
    external_test.go:524: ReadDir returned file: /tmp/66676782/a/b/d/foo
    external_test.go:529: Testing ReadDir with path containing '..': /tmp/66676782/a/b/c/foo
    external_test.go:538: 
        	Error Trace:	/home/runner/work/matrixone/matrixone/pkg/sql/colexec/external/external_test.go:538
        	Error:      	Expected nil, but got: &fs.PathError{Op:"lstat", Path:"/tmp/service-889346524-s1.sock", Err:0x2}
        	Test:       	TestReadDirSymlink
    external_test.go:540: 
        	Error Trace:	/home/runner/work/matrixone/matrixone/pkg/sql/colexec/external/external_test.go:540
        	Error:      	Not equal: 
        	            	expected: 1
        	            	actual  : 0
        	Test:       	TestReadDirSymlink
    external_test.go:405: Cleaning up temp directory: /tmp/66676782
--- FAIL: TestReadDirSymlink (0.04s)
panic: runtime error: index out of range [0] with length 0 [recovered, repanicked]

goroutine 277 [running]:
testing.tRunner.func1.2({0x53da3a0, 0xc003403170})
	/opt/hostedtoolcache/go/1.25.4/x64/src/testing/testing.go:1872 +0x419
testing.tRunner.func1()
	/opt/hostedtoolcache/go/1.25.4/x64/src/testing/testing.go:1875 +0x683
panic({0x53da3a0?, 0xc003403170?})
	/opt/hostedtoolcache/go/1.25.4/x64/src/runtime/panic.go:783 +0x132
github.com/matrixorigin/matrixone/pkg/sql/colexec/external.TestReadDirSymlink(0xc000bc2e00)
	/home/runner/work/matrixone/matrixone/pkg/sql/colexec/external/external_test.go:544 +0x2798
testing.tRunner(0xc000bc2e00, 0x574b2d8)
	/opt/hostedtoolcache/go/1.25.4/x64/src/testing/testing.go:1934 +0x21d
created by testing.(*T).Run in goroutine 1
	/opt/hostedtoolcache/go/1.25.4/x64/src/testing/testing.go:1997 +0x9d3
steps.ut.conclusion: failure
FAIL_UT_CASES=TestReadDirSymlink,

Expected Behavior

No response

Steps to Reproduce

ci test

Additional information

No response