Ports: Add libenet

Libenet is a UDP networking library that is used by Love2D,
a game framework I would like to port.

Ports/libenet/patches/0003-Fix-cmake-deprecation-warning.patch

@@ -0,0 +1,22 @@
+From 67f1ac3f2f1d2c24035bf8b2cd0a279158b94d2e Mon Sep 17 00:00:00 2001
+From: surrealegg <surrealegg@pm.me>
+Date: Thu, 21 Sep 2023 22:25:02 +0400
+Subject: [PATCH 3/3] Fix cmake deprecation warning
+
+---
+ CMakeLists.txt | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 532e628..6281d7e 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -1,4 +1,4 @@
+-cmake_minimum_required(VERSION 2.6)
++cmake_minimum_required(VERSION 2.8.12...3.20)
+ 
+ project(enet)
+ 
+-- 
+2.41.0
+