Polish Serialization Tests

If Instancio fails to instatiate the class sample, it will
now also delete the serialized sample file. Otherwise, it will
leave a zero-byte file on the filesystem, confusing future test runs

Author: jzheaux

config/src/test/java/org/springframework/security/SpringSecurityCoreVersionSerializableTests.java

@@ -775,10 +775,10 @@ void serializeCurrentVersionClasses(Class<?> clazz) throws Exception {
 			return;
 		}
 		Files.createFile(filePath);
-		Object instance = instancioWithDefaults(clazz).create();
-		assertThat(instance).isInstanceOf(clazz);
 		try (FileOutputStream fileOutputStream = new FileOutputStream(file);
 				ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream)) {
+			Object instance = instancioWithDefaults(clazz).create();
+			assertThat(instance).isInstanceOf(clazz);
 			objectOutputStream.writeObject(instance);
 			objectOutputStream.flush();
 		}