build: replace FetchContent with direct includes for toml++

include/toml++/impl/std_new.hpp

@@ -0,0 +1,18 @@
+//# This file is a part of toml++ and is subject to the the terms of the MIT license.
+//# Copyright (c) Mark Gillard <mark.gillard@outlook.com.au>
+//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
+// SPDX-License-Identifier: MIT
+#pragma once
+
+#include "preprocessor.hpp"
+TOML_DISABLE_WARNINGS;
+#include <new>
+TOML_ENABLE_WARNINGS;
+
+#if (!defined(__apple_build_version__) && TOML_CLANG >= 8) || TOML_GCC >= 7 || TOML_ICC >= 1910 || TOML_MSVC >= 1914
+#define TOML_LAUNDER(x) __builtin_launder(x)
+#elif defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606
+#define TOML_LAUNDER(x) std::launder(x)
+#else
+#define TOML_LAUNDER(x) x
+#endif