Make it ready for Java 25

[He-Pin]

Need to wait scala 2.13.17

[info] compiling 203 Scala sources and 27 Java sources to /Users/hepin/IdeaProjects/pekko/actor/target/scala-2.13/classes ...
[error] Error while emitting SameThreadExecutionContext.scala
[error] Unsupported class file major version 69
[error] Error while emitting ScalaBatchable.scala
[error] Unsupported class file major version 69
[error] Error while emitting ByteIterator.scala
[error] assertion failed: ClassBType.info not yet assigned: Ljava/lang/Object;
[error] Error while emitting ByteIterator.scala
[error] Unsupported class file major version 69