Flaky Test `TestLoggerPause`

[silverwind]

https://github.com/go-gitea/gitea/actions/runs/5055503857/jobs/9071789890?pr=24864

--- FAIL: TestLoggerPause (0.20s)
    logger_test.go:100: 
        	Error Trace:	/home/runner/work/gitea/gitea/modules/log/logger_test.go:100
        	Error:      	Not equal: 
        	            	expected: []string{}
        	            	actual  : []string{"info-level\n"}
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1,2 +1,3 @@
        	            	-([]string) {
        	            	+([]string) (len=1) {
        	            	+ (string) (len=11) "info-level\n"
        	            	 }
        	Test:       	TestLoggerPause

Maybe regression from #24726.

[wxiaoguang]

It needs a little "sleep", otherwise some writer hasn't been "paused"

Fix flakey test in logger test #24883