Add Default Member Initializer on value_storage_ as suggested by @t…

…koeppe:

#4877 (comment)

This fixes the errors reported under commit f07b28b.

include/pybind11/numpy.h

@@ -87,7 +87,7 @@ class LazyInitializeAtLeastOnceDestroyNever {
         = default;
 
 private:
-    alignas(T) char value_storage_[sizeof(T)];
+    alignas(T) char value_storage_[sizeof(T)] = {};
     bool initialized_ = false;
 };