Remove aligned_storage and the _t bug, closes #19

Argh, `_t`, now I see the typo-that-compiles. Yup, that's too subtle, and as was pointed out `aligned_storage` is deprecated in C++23... I'm convinced now

Author: hsutter

include/cpp2util.h

@@ -384,7 +384,7 @@ using in =
 template<typename T>
 class deferred_init {
     bool init = false;
-    std::aligned_storage<sizeof(T), alignof(T)> data; // or: alignas(T) std::byte data[sizeof(T)];
+    alignas(T) std::byte data[sizeof(T)]; // or: std::aligned_storage_t<sizeof(T), alignof(T)> data
 
     auto t() -> T& { return *std::launder(reinterpret_cast<T*>(&data)); }