In which type of environment might water soluble rocks such as limestone or dolostone become ridge formers?

I would say that the most likely environment for these two rock types to be ridge formers would be an arid climate like a desert where there was little water to dissolve. Also, even in a normal temperate environment, dolomite can form a very resistant ridge or cliff former as is the case with the Palliser Formation in Banff Park which forms a pronounced cliff which is very extensive.