OpenRewrite recipe best practices (#997)

* OpenRewrite recipe best practices

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.recipes.rewrite.OpenRewriteRecipeBestPractices?organizationId=QUxML01vZGVybmUvTW9kZXJuZSArIE9wZW5SZXdyaXRl

Co-authored-by: Moderne <team@moderne.io>

* Update JUnit6BestPracticesTest.java

---------

Co-authored-by: Moderne <team@moderne.io>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: 3 people

src/test/java/org/openrewrite/java/testing/junit/JUnit6BestPracticesTest.java

@@ -100,10 +100,7 @@ void test2() {
                   </dependencyManagement>
               </project>
               """,
-            spec -> spec.after(actual -> {
-                return assertThat(actual)
-                        .containsPattern("<junit-jupiter\\.version>6\\.\\d+\\.\\d+</junit-jupiter\\.version>").actual();
-            })
+            spec -> spec.after(actual -> assertThat(actual).containsPattern("<junit-jupiter\\.version>6\\.\\d+\\.\\d+</junit-jupiter\\.version>").actual())
           )
         );
     }