Fix missing "since" attributes for Deprecated code

See gh-34989

spring-core-test/src/main/java/org/springframework/aot/agent/InstrumentedBridgeMethods.java

@@ -44,7 +44,7 @@ import org.jspecify.annotations.Nullable;
  * @deprecated This class should only be used by the runtime-hints agent when instrumenting bytecode
  * and is not considered public API.
  */
-@Deprecated
+@Deprecated(since = "6.0")
 public abstract class InstrumentedBridgeMethods {
 
 	private InstrumentedBridgeMethods() {

spring-core-test/src/main/java/org/springframework/aot/agent/RuntimeHintsAgent.java

@@ -43,7 +43,7 @@ import org.springframework.util.StringUtils;
  * @deprecated as of 7.0 in favor of the {@code -XX:MissingRegistrationReportingMode=Warn} and
  * {@code -XX:MissingRegistrationReportingMode=Exit} JVM flags with GraalVM.
  */
-@Deprecated(forRemoval = true)
+@Deprecated(since = "7.0", forRemoval = true)
 public final class RuntimeHintsAgent {
 
 	private static boolean loaded = false;

spring-core-test/src/main/java/org/springframework/aot/test/agent/RuntimeHintsRecorder.java

@@ -34,7 +34,7 @@ import org.springframework.util.Assert;
  * @deprecated as of 7.0 in favor of the {@code -XX:MissingRegistrationReportingMode=Warn} and
  * {@code -XX:MissingRegistrationReportingMode=Exit} JVM flags with GraalVM.
  */
-@Deprecated(forRemoval = true)
+@Deprecated(since = "7.0", forRemoval = true)
 @SuppressWarnings("removal")
 public final class RuntimeHintsRecorder {