Government debt across developed economies is set to climb to a record $75.8 trillion by the end of 2026 as countries struggle with persistent budget deficits, geopolitical tensions and rising spending demands, Fitch Ratings said on Tuesday. The ratings agency said debt in developed markets would increase by $4.2 trillion this year alone, taking the total to the equivalent of 104% of gross domestic product, up sharply from $26 trillion, or 68% of GDP, two decades ago. Fitch expects…