IWYU failure with gcc15[1]. Fixed in both upstreams but bundled
copies are outdated.

Backport of [2], and partial backport of [3] which added the header.

[1] https://bugs.gentoo.org/940190
[2] https://github.com/KhronosGroup/glslang/commit/e40c14a3e007fac0e4f2e4164fdf14d1712355bd
[3] https://github.com/thorvg/thorvg/commit/ed01ef717e983f7c53e1cdfb0a68b02ae4b19375
--- a/thirdparty/glslang/SPIRV/SpvBuilder.h
+++ b/thirdparty/glslang/SPIRV/SpvBuilder.h
@@ -58,2 +58,3 @@
 #include <algorithm>
+#include <cstdint>
 #include <map>
--- a/thirdparty/thorvg/inc/thorvg.h
+++ b/thirdparty/thorvg/inc/thorvg.h
@@ -3,2 +3,3 @@
 
+#include <cstdint>
 #include <functional>