Actually, they didn't. From your link:
"The proposition that the earth is not the center of the world, nor immovable, but that it moves, and also with a diurnal action, is also absurd, philosophically false, and, theologically considered, at least erroneous in faith."
"Erroneous in faith" is a fancy way of saying contrary to the eccelsiastical consensus opinion. It's quite a different thing from heresy. It's an important difference because ecclesiastical consensus opinion is not irreformable, and often does change. On the other hand, heresy is a doctrine that is contrary to irreformable dogma.
Of course, they did declare as heresy the proposition that the sun is the center of the universe, but on this they were absolutely correct.
This discussion is descending into trivia. Yes, the sun isn't the center of the universe; but they "knew" this from scripture, which implies that it moves around the earth, and we know it for very different reasons. You get no points for that.
The sentence you quoted was quoted correctly: "The proposition that the earth is not the center of the world, nor immovable, but that it moves, and also with a diurnal action, is also absurd, philosophically false, and, theologically considered, at least erroneous in faith."
However, the indictment goes on to say this:
... We pronounce, judge, and declare, that you, the said Galileo . . . have rendered yourself vehemently suspected by this Holy Office of heresy, that is, of having believed and held the doctrine (which is false and contrary to the Holy and Divine Scriptures) that the sun is the center of the world, and that it does not move from east to west, and that the earth does move, and is not the center of the world; also, that an opinion can be held and supported as probable, after it has been declared and finally decreed contrary to the Holy Scripture, and, consequently, that you have incurred all the censures and penalties ...So it looks like the heliocentric model was heresy, and it's quibbling to say whether it was Galileo's opinion on the motion of the earth or the immobility of the sun that did him in. It seems to be the whole package.