[C23] Update status page for TS 18661 integration (#105693)
WG14 N2401 was removed from the list because it was library-only changes
that don't impact the compiler.
Everything having to do with decimal floating-point types was changed to
No because we do not currently have any support for those.
WG14 N2314 remains Unknown because it has changes to Annex F for binary
floating-point types.