re-enable constant list elems?

[rurban]

See https://rt.perl.org//Public/Bug/Display.html?id=119045. Fixing Text::Aligner is trivial via distroprefs or a patch.

Revert f99a5f08f203af84430e677e25df49557c55c24f

but the question is if this is really a good idea. The list is readonly already. cperl :const does only shallow consting.