KEP-3673: Acknowlege a requirement in test plan

Author: ruiwen-zhao

keps/sig-node/3673-kubelet-parallel-image-pull-limit/README.md

@@ -312,7 +312,7 @@ when drafting this test plan.
 [testing-guidelines]: https://git.k8s.io/community/contributors/devel/sig-testing/testing.md
 -->
 
-[ ] I/we understand the owners of the involved components may require updates to
+[X] I/we understand the owners of the involved components may require updates to
 existing tests to make this code solid enough prior to committing the changes necessary
 to implement this enhancement.