Unbundle spng, miniz
*** a/third-party/CMakeLists.txt
--- b/third-party/CMakeLists.txt
@@ -4,20 +4,13 @@
 target_woof_settings(md5)
 target_include_directories(md5 INTERFACE md5)
 
-add_library(miniz STATIC miniz/miniz.c)
-target_woof_settings(miniz)
-target_compile_definitions(miniz PRIVATE MINIZ_NO_TIME)
-target_include_directories(miniz INTERFACE miniz)
+find_package(miniz)
 
 add_library(pffft STATIC pffft/pffft.c)
 target_woof_settings(pffft)
 target_include_directories(pffft INTERFACE pffft)
 
-add_library(spng STATIC spng/spng.c)
-target_woof_settings(spng)
-target_compile_definitions(spng PRIVATE SPNG_USE_MINIZ INTERFACE SPNG_STATIC)
-target_include_directories(spng INTERFACE spng)
-target_link_libraries(spng miniz)
+find_package(spng)
 
 if(NOT yyjson_FOUND)
     add_library(yyjson STATIC yyjson/yyjson.c)