From: Pavel Sobolev <contact@paveloom.dev>
Subject: [PATCH] Use the system `sirit` library.

Signed-off-by: Pavel Sobolev <contact@paveloom.dev>

--- a/externals/CMakeLists.txt
+++ b/externals/CMakeLists.txt
@@ -452,7 +452,7 @@ if (ENABLE_VULKAN)
     endif()
 
     # sirit
-    add_subdirectory(sirit EXCLUDE_FROM_ALL)
+    find_package(sirit REQUIRED)
 
     # VMA
     if(USE_SYSTEM_VMA)