8255989: Remove explicitly unascribed authorship from Java source files

Reviewed-by: redestad, mr, mchung, iris, serb

src/java.base/share/classes/java/lang/Throwable.java

@@ -106,7 +106,6 @@ import java.util.*;
  * {@code String} (the detail message) and a {@code Throwable} (the
  * cause).
  *
- * @author  unascribed
  * @author  Josh Bloch (Added exception chaining and programmatic access to
  *          stack trace in 1.4.)
  * @jls 11.2 Compile-Time Checking of Exceptions