$NetBSD$

Use the platform appropriate dlopen flags and libraries.

--- libraries/ZVulkan/CMakeLists.txt.orig	2023-10-26 19:18:50.000000000 +0000
+++ libraries/ZVulkan/CMakeLists.txt
@@ -188,9 +188,9 @@ if(WIN32)
 	add_definitions(-DUNICODE -D_UNICODE)
 else()
 	set(ZVULKAN_SOURCES ${ZVULKAN_SOURCES} ${ZVULKAN_UNIX_SOURCES})
-	set(ZVULKAN_LIBS ${CMAKE_DL_LIBS} -ldl)
+	set(ZVULKAN_LIBS ${CMAKE_DL_LIBS} ${DL_LIBS})
 	add_definitions(-DUNIX -D_UNIX)
-	add_link_options(-pthread)
+	add_link_options(-pthread ${DL_LDFLAGS})
 endif()
 
 if(MSVC)