As talk of privatization swirls, the head of Toronto’s Pearson airport says the existing public ownership model has served travellers well — but she remains open to “enhancements” that tap into private-sector investment. Deborah Flint, CEO of the Greater Toronto Airports Authority, said in an interview she shares the federal government’s goal of growing Pearson’s capital value, but that the current framework has proven its worth by steering Cana…