After losing a Toronto-area riding the Liberals have held for more than three decades, Prime Minister Justin Trudeau said Tuesday he heard the “concerns and frustrations” of voters. His party, pollsters and even Conservatives had considered Toronto-St. Paul’s to be a relatively safe seat for the Liberals as voters headed to cast ballots in a byelection Monday. But by the wee hours of Tuesday, the Conservative candidate took a narrow lead and clinched the seat — the first time the Tories have won in Toronto proper since 2011. The upset has sparked questions about the political prospects of Trudeau and his Liberals, whose polling numbers across Canada are down around their ankles. “These are not easy times, and it is clear I, and my entire Liberal team, have much more…