Add missing serialVersionUID declarations in tests

src/test/java/org/apache/commons/lang3/AnnotationUtilsTest.java

@@ -388,6 +388,8 @@ public class AnnotationUtilsTest {
         long timeout() default 0L;
 
         class None extends Throwable {
+
+            private static final long serialVersionUID = 1L;
         }
     }
 

src/test/java/org/apache/commons/lang3/exception/CustomCheckedException.java

@@ -19,6 +19,8 @@ package org.apache.commons.lang3.exception;
 
 public class CustomCheckedException extends Exception {
 
+    private static final long serialVersionUID = 1L;
+
     public CustomCheckedException() {
         super();
     }

src/test/java/org/apache/commons/lang3/exception/CustomUncheckedException.java

@@ -19,6 +19,8 @@ package org.apache.commons.lang3.exception;
 
 public class CustomUncheckedException extends RuntimeException {
 
+    private static final long serialVersionUID = 1L;
+
     public CustomUncheckedException() {
         super();
     }

src/test/java/org/apache/commons/lang3/exception/ExceptionUtilsTest.java

@@ -702,6 +702,8 @@ public class ExceptionUtilsTest {
     @DisplayName("getStackFrames returns empty string array when the argument is null")
     public void testgetStackFramesHappyPath() {
         final String[] actual = ExceptionUtils.getStackFrames(new Throwable() {
+            private static final long serialVersionUID = 1L;
+
             // provide static stack trace to make test stable
             @Override
             public void printStackTrace(final PrintWriter s) {