Use test context in tests and new loop system in benchmarks (#33648)

Replace all contexts in tests with go1.24 t.Context()

---------

Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/markup/html_test.go

@@ -522,7 +522,7 @@ func BenchmarkEmojiPostprocess(b *testing.B) {
 		data += data
 	}
 	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		var res strings.Builder
 		err := markup.PostProcessDefault(markup.NewTestRenderContext(localMetas), strings.NewReader(data), &res)
 		assert.NoError(b, err)