Fix complex math pow test (#2336)

Increase the margin for results comparisn for single precision floating
point operations due to high computing error compared to `std::pow`.

test/unit/math/src/TestTemplate.hpp

@@ -177,7 +177,7 @@ namespace mathtest
             if(!isFinite(a) && !isFinite(b))
                 return true;
             // For the same reason use relative difference comparison with a large margin
-            auto const scalingFactor = static_cast<T>(std::is_same_v<T, float> ? 1.1e4 : 1.1e6);
+            auto const scalingFactor = static_cast<T>(std::is_same_v<T, float> ? 1.5e4 : 1.1e6);
             auto const marginValue = scalingFactor * std::numeric_limits<T>::epsilon();
             return (a.real() == Catch::Approx(b.real()).margin(marginValue).epsilon(marginValue))
                    && (a.imag() == Catch::Approx(b.imag()).margin(marginValue).epsilon(marginValue));