Deprecate org.springframework.core.Constants utility

Closes gh-30851

spring-core/src/main/java/org/springframework/core/Constants.java

@@ -43,7 +43,10 @@ import org.springframework.util.ReflectionUtils;
  * @author Rod Johnson
  * @author Juergen Hoeller
  * @since 16.03.2003
+ * @deprecated since 6.1 with no replacement; use an enum, map, or similar custom
+ * solution instead
  */
+@Deprecated(since = "6.1")
 public class Constants {
 
 	/** The name of the introspected class. */

spring-core/src/test/java/org/springframework/core/ConstantsTests.java

@@ -31,6 +31,7 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
  * @author Rick Evans
  * @since 28.04.2003
  */
+@SuppressWarnings("deprecation")
 class ConstantsTests {
 
 	@Test