Main class detection: recognize simpler main methods in Java 25 (JEP-512)

[lrytz]

$> cat T.scala
class A {
  def main(): Unit = println(1)
}

$> scala-cli T.scala
Compiling project (Scala 3.7.3, JVM (25))
Compiled project (Scala 3.7.3, JVM (25))
[error]  No main class found

$> sc T.scala
> scala compile --server=false -S 2.13 -d . -release 8 T.scala

$> jar cf run.jar A.class

$> scala-cli -S 2.13.16 run.jar
[error]  No main class found

cf https://github.com/sbt/sbt/issues/7384

[xuwei-k]

https://github.com/VirtusLab/scala-cli/blob/eaa671eaf290aef5967da8a17728b6856c52b04e/modules/build/src/main/scala/scala/build/internal/MainClass.scala#L38-L40