LibFileSystem: Fix Windows build

This reverts part of  b3c253e50fe630bdf6907fd0641c58975cbcebc5

Libraries/LibFileSystem/FileSystem.cpp

@@ -15,6 +15,8 @@
 #    include <sys/disk.h>
 #elif defined(AK_OS_LINUX)
 #    include <linux/fs.h>
+#elif defined(AK_OS_WINDOWS)
+#    include <dirent.h>
 #endif
 
 // On Linux distros that use glibc `basename` is defined as a macro that expands to `__xpg_basename`, so we undefine it