TestGetTSOImmediately is unstable

[lhy1024]

Flaky Test

Which jobs are failing

2023-07-05T10:46:38.9667482Z     keyspace_group_manager_test.go:744: 
2023-07-05T10:46:38.9667990Z         	Error Trace:	/home/runner/work/pd/pd/tests/integrations/mcs/tso/keyspace_group_manager_test.go:744
2023-07-05T10:46:38.9668660Z         	            				/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/asm_amd64.s:1598
2023-07-05T10:46:38.9668912Z         	Error:      	Received unexpected error:
2023-07-05T10:46:38.9669363Z         	            	primary of keyspace group does not exist
2023-07-05T10:46:38.9669779Z         	            	github.com/tikv/pd/pkg/keyspace.init
2023-07-05T10:46:38.9670451Z         	            		/home/runner/work/pd/pd/pkg/keyspace/util.go:99
2023-07-05T10:46:38.9670701Z         	            	runtime.doInit
2023-07-05T10:46:38.9671376Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6506
2023-07-05T10:46:38.9672047Z         	            	runtime.doInit
2023-07-05T10:46:38.9673325Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9673629Z         	            	runtime.doInit
2023-07-05T10:46:38.9674388Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9674679Z         	            	runtime.doInit
2023-07-05T10:46:38.9675580Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9675938Z         	            	runtime.doInit
2023-07-05T10:46:38.9677071Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9677332Z         	            	runtime.doInit
2023-07-05T10:46:38.9678012Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9678276Z         	            	runtime.doInit
2023-07-05T10:46:38.9679131Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:6483
2023-07-05T10:46:38.9679492Z         	            	runtime.main
2023-07-05T10:46:38.9680180Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/proc.go:233
2023-07-05T10:46:38.9680538Z         	            	runtime.goexit
2023-07-05T10:46:38.9681180Z         	            		/opt/hostedtoolcache/go/1.20.1/x64/src/runtime/asm_amd64.s:1598
2023-07-05T10:46:38.9681415Z         	Test:       	TestGetTSOImmediately

CI link

https://github.com/tikv/pd/actions/runs/5463258824/jobs/9943718192

Reason for failure (if possible)

Anything else

[lhy1024]

	testutil.Eventually(re, func() bool {
		p0, err := kgm.GetKeyspaceGroupPrimaryByID(0)
		re.NoError(err)
		p1, err := kgm.GetKeyspaceGroupPrimaryByID(1)
		re.NoError(err)
		return p0 == kg0.Members[0].Address && p1 == kg1.Members[1].Address
	}, testutil.WithWaitFor(5*time.Second), testutil.WithTickInterval(50*time.Millisecond))

Maybe we can skip error check for kgm.GetKeyspaceGroupPrimaryByID(1) in testutil.Eventually