test: Flaky TestAPMServerInstrumentation on main

[carsonip]

main
example: https://github.com/elastic/apm-server/actions/runs/20752416847/job/59585130574?pr=20080

 === RUN   TestAPMServerInstrumentation
    instrumentation_test.go:92: 
        	Error Trace:	/home/runner/work/apm-server/apm-server/systemtest/instrumentation_test.go:92
        	Error:      	Not equal: 
        	            	expected: "5c926d8186d5f4ecffde6dbafba2081c"
        	            	actual  : "24f354f2ed39bc1ca25498920cdbacb5"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1 +1 @@
        	            	-5c926d8186d5f4ecffde6dbafba2081c
        	            	+24f354f2ed39bc1ca25498920cdbacb5
        	Test:       	TestAPMServerInstrumentation
        	Messages:   	expecting log with trace id 5c926d8186d5f4ecffde6dbafba2081c; got trace id 24f354f2ed39bc1ca25498920cdbacb5 and message "request ok" instead
    instrumentation_test.go:94: 
        	Error Trace:	/home/runner/work/apm-server/apm-server/systemtest/instrumentation_test.go:94
        	Error:      	Not equal: 
        	            	expected: "5c926d8186d5f4ec"
        	            	actual  : "24f354f2ed39bc1c"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1 +1 @@
        	            	-5c926d8186d5f4ec
        	            	+24f354f2ed39bc1c
        	Test:       	TestAPMServerInstrumentation
        	Messages:   	expecting log with transaction id 5c926d8186d5f4ec; got transaction id 24f354f2ed39bc1c and message "request ok" instead
    server.go:144: log file: /home/runner/work/apm-server/apm-server/systemtest/logs/TestAPMServerInstrumentation/apm-server
--- FAIL: TestAPMServerInstrumentation (1.71s)

[carsonip]

duplicate of #17309