Wayland: Fix OSMesa library not being unloaded

(cherry picked from commit 2d281d7928)

README.md

@@ -141,6 +141,7 @@ information on what to include when reporting a bug.
  - [Wayland] Bugfix: Some errors would cause clipboard string transfer to hang
  - [Wayland] Bugfix: Drag and drop data was misinterpreted as clipboard string
  - [Wayland] Bugfix: MIME type matching was not performed for clipboard string
+ - [Wayland] Bugfix: The OSMesa library was not unloaded on termination
 
 
 ## Contact

src/wl_init.c

@@ -484,6 +484,8 @@ void _glfwPlatformTerminate(void)
     _glfwTerminateJoysticksLinux();
 #endif
     _glfwTerminateEGL();
+    _glfwTerminateOSMesa();
+
     if (_glfw.wl.egl.handle)
     {
         _glfw_dlclose(_glfw.wl.egl.handle);