[Bug libstdc++/121348] `vector::resize(n, value)` incorrectly requires the element type to be assignable

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121348

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://cplusplus.github.io/LWG/lwg-defects.html#2323

Change it to just:
equires: T shall be CopyInsertable into *this.

So this looks like it was changed for C++20.