package/less: bump to version 608
For change log, see:
https://www.greenwoodsoftware.com/less/news.608.html
Note 1: the package patch is kept, as it is included in version 609.
Note 2: the license file hash changed due to the year update.
Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>