Fix formatting in testing best practices

doc/development/testing_guide/best_practices.md

@@ -994,6 +994,7 @@ Only use simple values as input in the `where` block. Using
 objects, FactoryBot-created objects, and similar items can lead to
 [unexpected results](https://github.com/tomykaira/rspec-parameterized/issues/8).
 <!-- vale gitlab.Spelling = YES -->
+
 ### Prometheus tests
 
 Prometheus metrics may be preserved from one test run to another. To ensure that metrics are