core: Move to C++26 and use native_handle to CLOEXEC the debug fd (#7219)

Requires GCC >= 14 / Clang >= 18

---------

Co-authored-by: Mihai Fufezan <mihai@fufexan.net>

src/debug/Log.cpp

@@ -5,10 +5,13 @@
 
 #include <fstream>
 #include <iostream>
+#include <fcntl.h>
 
 void Debug::init(const std::string& IS) {
     logFile = IS + (ISDEBUG ? "/hyprlandd.log" : "/hyprland.log");
     logOfs.open(logFile, std::ios::out | std::ios::app);
+    auto handle = logOfs.native_handle();
+    fcntl(handle, F_SETFD, FD_CLOEXEC);
 }
 
 void Debug::close() {