Remove #include <stdalign.h>

* `include\pybind11/numpy.h(24,10): fatal error C1083: Cannot open include file: 'stdalign.h': No such file or directory`

* @tkoeppe wrote: this is a C interop header (and we're not writing C)

Author: rwgk

include/pybind11/numpy.h

@@ -21,7 +21,6 @@
 #include <functional>
 #include <numeric>
 #include <sstream>
-#include <stdalign.h>
 #include <string>
 #include <type_traits>
 #include <typeindex>