Fix JUnit5MigrationTest.addMockitoJupiterDependencyIfExtendWithPresent (#931)

The upstream AddDependency recipe now correctly scopes onlyIfUsing checks to match the dependency's scope. Test-scoped dependencies are only added when the usage is detected in test sources, so move the test class from main sources to test sources.

Co-authored-by: Tim te Beek <tim@device-97.home>

Author: timtebeek

src/test/java/org/openrewrite/java/testing/junit5/JUnit5MigrationTest.java

@@ -596,7 +596,7 @@ void addMockitoJupiterDependencyIfExtendWithPresent() {
               .build()
               .activateRecipes("org.openrewrite.java.testing.junit5.UseMockitoExtension")),
           mavenProject("sample",
-            srcMainJava(
+            srcTestJava(
               //language=java
               java(
                 """