unstable test TestResourceGroupRunaway

[hawkingrei]

Bug Report

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1. Minimal reproduce step (Required)

2. What did you expect to see? (Required)

3. What did you see instead (Required)

 [2023/06/21 18:38:34.445 +08:00] [INFO] [db.go:625] ["Waiting for closer"]
--- FAIL: TestResourceGroupRunaway (31.28s)
    resource_group_test.go:255: 
        	Error Trace:	ddl/tests/resourcegroup/resource_group_test.go:255
        	Error:      	"[[rg1 select /*+ resource_group(rg1) */ * from t 2023-06-21 18:38:31]]" should have 0 item(s), but has 1
        	Test:       	TestResourceGroupRunaway
FAIL

4. What is your TiDB version? (Required)

[CabinfeverB]

/assigned