refactor: Remove public visibility of JUnit 5 tests

Use this link to re-run the recipe: https://app.moderne.io/recipes/org.openrewrite.java.testing.cleanup.TestsShouldNotBePublic?organizationId=T3BlblJld3JpdGU%3D

Co-authored-by: Moderne <[email protected]>

src/test/java/org/openrewrite/analysis/InvocationMatcherTest.java

@@ -27,7 +27,7 @@
 
 import static org.openrewrite.java.Assertions.java;
 
-public class InvocationMatcherTest implements RewriteTest {
+class InvocationMatcherTest implements RewriteTest {
 
     static JavaIsoVisitor<ExecutionContext> matcherVisitor(Predicate<Cursor> match) {
         return new JavaIsoVisitor<>() {

src/test/java/org/openrewrite/analysis/dataflow/ExternalFlowModelsTest.java

@@ -23,7 +23,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-public class ExternalFlowModelsTest {
+class ExternalFlowModelsTest {
     @Test
     void listFlowModelsOptimized() {
         final var externalFlowModels = ExternalFlowModels.instance();

src/test/java/org/openrewrite/analysis/dataflow/ExternalModelMethodMatcherTest.java

@@ -30,7 +30,7 @@
 import static org.openrewrite.test.RewriteTest.toRecipe;
 
 @SuppressWarnings({"ResultOfMethodCallIgnored", "UnnecessaryCallToStringValueOf", "StringOperationCanBeSimplified"})
-public class ExternalModelMethodMatcherTest implements RewriteTest {
+class ExternalModelMethodMatcherTest implements RewriteTest {
     static Supplier<TreeVisitor<?, ExecutionContext>> fromModel(
       String namespace,
       String type,

src/test/java/org/openrewrite/analysis/dataflow/ExternalSinkModelsTest.java

@@ -22,7 +22,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-public class ExternalSinkModelsTest {
+class ExternalSinkModelsTest {
 
     @Test
     void listSinkModelsOptimized() {

src/test/java/org/openrewrite/analysis/search/UsesAllInvocationsTest.java

@@ -24,7 +24,7 @@
 import static org.openrewrite.java.Assertions.java;
 
 @LoathingOfOthers("This is basically a copy-paste of UsesAllMethodsTest.java in rewrite-java-test")
-public class UsesAllInvocationsTest implements RewriteTest {
+class UsesAllInvocationsTest implements RewriteTest {
 
     @DocumentExample
     @Test

src/test/java/org/openrewrite/analysis/trait/variable/ParameterTest.java

@@ -34,7 +34,7 @@
 import static org.openrewrite.java.Assertions.java;
 import static org.openrewrite.test.RewriteTest.toRecipe;
 
-public class ParameterTest implements RewriteTest {
+class ParameterTest implements RewriteTest {
 
     static Supplier<TreeVisitor<?, ExecutionContext>> visitVariable(
       BiFunction<J.VariableDeclarations.NamedVariable, Cursor, J.VariableDeclarations.NamedVariable> visitor