Add missing <tuple> include

ranges.h needs std::get overloads from <tuple> but does not directly
include it. This causes compilation failures in MSVC with /permissive-.
On other platforms <tuple> is included as a dependency from other headers
(specifically from <memory>), but there is no such implicit dependency in
MSVC's STL.

Fixes #2401

include/fmt/ranges.h

@@ -13,6 +13,7 @@
 #define FMT_RANGES_H_
 
 #include <initializer_list>
+#include <tuple>
 #include <type_traits>
 
 #include "format.h"