Pittsburgh (AFP) – A bridge collapse Friday in Pittsburgh provided a symbolic backdrop for President Joe Biden’s trip to the city to tout his $1 trillion infrastructure plan — and try rebuilding his own crumbling approval ratings. Arriving in the gritty city in Pennsylvania — a key battleground state in presidential elections — Biden motorcaded straight from Air Force One to the road bridge, which hours earlier had buckled into a snowy ravine. “There are literally more bridges in Pittsburgh than in any other city in the world,” the Democrat pronounced. “And we’re going to fix them all. Not …