yaml-cpp: fix build with gcc15

- add patch from merged upstream PR that adds `include <ctdint>`:
https://www.github.com/jbeder/yaml-cpp/pull/1310
https://github.com/jbeder/yaml-cpp/commit/7b469b4220f96fb3d036cf68cd7bd30bd39e61d2

Fixes build failure with gcc15:
```
/build/source/src/emitterutils.cpp:221:11: error: 'uint16_t' was not declared in this scope
221 | std::pair<uint16_t, uint16_t> EncodeUTF16SurrogatePair(int codePoint) {
| ^~~~~~~~
/build/source/src/emitterutils.cpp:13:1: note: 'uint16_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
12 | #include "yaml-cpp/null.h"
+++ |+#include <cstdint>
13 | #include "yaml-cpp/ostream_wrapper.h"
```

pkgs/by-name/ya/yaml-cpp/package.nix

···
       url = "https://github.com/jbeder/yaml-cpp/commit/c2680200486572baf8221ba052ef50b58ecd816e.patch";
       hash = "sha256-1kXRa+xrAbLEhcJxNV1oGHPmayj1RNIe6dDWXZA3mUA=";
     })
+    # Fix build with gcc15
+    # https://github.com/jbeder/yaml-cpp/pull/1310
+    (fetchpatch {
+      name = "yaml-cpp-add-include-cstdint-gcc15.patch";
+      url = "https://github.com/jbeder/yaml-cpp/commit/7b469b4220f96fb3d036cf68cd7bd30bd39e61d2.patch";
+      hash = "sha256-4Mua6cYD8UR+fJfFeu0fdYVFprsiuF89HvbaTByz9nI=";
+    })
   ];
 
   strictDeps = true;