How does energy (from fusion reactions still inside the sun) still have gravitational attraction?
I think it is best not to think of energy having a gravitational attraction, rather that energy, like mass, (since they are equivalent keeping in mind c) will curve spacetime.  Electric charges, magnets, and electromagnetic fields will curve spacetime, Scientific American. So whether it is mass or energy, they both will affect the curvature of spacetime, and the sun's total impact on spacetime will not change.