[Bug libstdc++/102280] span's range deduction guide is missing ranges::contiguous_range constraint

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102280

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I've set the Target Milestone field to indicate is going to be fixed for 10.4