UT of meta sometimes fails

[jiacai2050]

Describe this problem

--- FAIL: TestWatch (0.82s)
    watch_test.go:68: 
        	Error Trace:	/home/runner/work/incubator-horaedb/incubator-horaedb/horaemeta/server/coordinator/watch/watch_test.go:68
        	Error:      	Not equal: 
        	            	expected: 2
        	            	actual  : 0
        	Test:       	TestWatch
FAIL
coverage: 30.2% of statements

Server version

commit dc38488ff9e540087069feea7d26727a1c942ee8

Steps to reproduce

Just run go test in meta, this issue is not 100% reproducible.

Expected behavior

No error.

Additional Information

https://github.com/apache/incubator-horaedb/actions/runs/8844259737/job/24285819263?pr=1524