TestRedirect is flaky

[okJiang]

Flaky Test

Which jobs are failing

api_test.go:631: 
        	Error Trace:	/home/runner/work/pd/pd/tests/server/api/api_test.go:631
        	Error:      	Received unexpected error:
        	            	[PD:etcd:ErrEtcdMoveLeader]etcdserver: request timed out, leader transfer took too long: etcdserver: request timed out, leader transfer took too long
        	            	github.com/pingcap/errors.AddStack
        	            		/home/runner/go/pkg/mod/github.com/pingcap/[email protected]/errors.go:174
        	            	github.com/pingcap/errors.(*Error).GenWithStackByCause
        	            		/home/runner/go/pkg/mod/github.com/pingcap/[email protected]/normalize.go:307
        	            	github.com/tikv/pd/pkg/member.(*EmbeddedEtcdMember).MoveEtcdLeader
        	            		/home/runner/work/pd/pd/pkg/member/member.go:317
        	            	github.com/tikv/pd/pkg/member.(*EmbeddedEtcdMember).ResignEtcdLeader
        	            		/home/runner/work/pd/pd/pkg/member/member.go:379
        	            	github.com/tikv/pd/tests.(*TestServer).ResignLeader
        	            		/home/runner/work/pd/pd/tests/cluster.go:172
        	            	github.com/tikv/pd/tests/server/api.(*redirectorTestSuite).TestRedirect
        	            		/home/runner/work/pd/pd/tests/server/api/api_test.go:630
        	            	reflect.Value.call
        	            		/opt/hostedtoolcache/go/1.23.2/x64/src/reflect/value.go:[581](https://github.com/tikv/pd/actions/runs/11341558936/job/31546401288?pr=8707#step:4:582)
        	            	reflect.Value.Call
        	            		/opt/hostedtoolcache/go/1.23.2/x64/src/reflect/value.go:365
        	            	github.com/stretchr/testify/suite.Run.func1
        	            		/home/runner/go/pkg/mod/github.com/stretchr/[email protected]/suite/suite.go:202
        	            	testing.tRunner
        	            		/opt/hostedtoolcache/go/1.23.2/x64/src/testing/testing.go:1690
        	            	runtime.goexit
        	            		/opt/hostedtoolcache/go/1.23.2/x64/src/runtime/asm_amd64.s:1700
        	Test:       	TestRedirectorTestSuite/TestRedirect
=== RUN   TestRedirectorTestSuite/TestXForwardedFor

CI link

https://github.com/tikv/pd/actions/runs/11341558936/job/31546401288?pr=8707

Reason for failure (if possible)

Anything else