`TestConfigController` is flaky

[rleungx]

Flaky Test

Which jobs are failing

2024-04-08T03:05:00.1294129Z === RUN   TestResourceManagerSuite/TestConfigController
2024-04-08T03:05:00.1294911Z     resource_manager_command_test.go:71: 
2024-04-08T03:05:00.1295979Z         	Error Trace:	/home/runner/work/pd/pd/tools/pd-ctl/tests/resourcemanager/resource_manager_command_test.go:71
2024-04-08T03:05:00.1297585Z         	            				/home/runner/work/pd/pd/tools/pd-ctl/tests/resourcemanager/resource_manager_command_test.go:76
2024-04-08T03:05:00.1298338Z         	Error:      	Received unexpected error:
2024-04-08T03:05:00.1299117Z         	            	invalid character 'G' looking for beginning of value
2024-04-08T03:05:00.1299759Z         	Test:       	TestResourceManagerSuite/TestConfigController
2024-04-08T03:05:00.1300271Z --- FAIL: TestResourceManagerSuite (50.13s)
2024-04-08T03:05:00.1300858Z     --- FAIL: TestResourceManagerSuite/TestConfigController (0.00s)
2024-04-08T03:05:00.1301280Z FAIL
2024-04-08T03:05:00.1301523Z coverage: [no statements]
2024-04-08T03:05:00.1302017Z FAIL	github.com/tikv/pd/tools/pd-ctl/tests/resourcemanager	50.279s

CI link

https://github.com/tikv/pd/actions/runs/8593935349/job/23546210799?pr=8033

Reason for failure (if possible)

Anything else