Remove @Deprecated from package-info.java file (#8591)

Motivation:

31fd66b617 added @Deprecated to some classes but also to the package-info.java files. IntelliJ does not like to have these annotations on package-info.java

Modifications:

Remove annotation from package-info.java

Result:

Be able to compile against via IntelliJ

transport-sctp/src/main/java/io/netty/channel/sctp/oio/package-info.java

@@ -20,5 +20,4 @@
  *
  * @deprecated use NIO based SCTP implementation.
  */
-@Deprecated
 package io.netty.channel.sctp.oio;

transport/src/main/java/io/netty/channel/oio/package-info.java

@@ -20,5 +20,4 @@
  *
  * @deprecated use NIO / EPOLL / KQUEUE transport.
  */
-@Deprecated
 package io.netty.channel.oio;

transport/src/main/java/io/netty/channel/socket/oio/package-info.java

@@ -20,5 +20,4 @@
  *
  * @deprecated use NIO / EPOLL / KQUEUE transport.
  */
-@Deprecated
 package io.netty.channel.socket.oio;