Whether you look at it in terms of absolute or relative motion, the implication is made that both the sun and the moon were moving.
absolute motion:
~ whether the earth was moving or not, the sun and moon move naturally by default
relative motion:
~ if the earth was moving, the sun and moon would have to move in-sync with the earth movements so precisely as to create the appearance of not moving.
Considering how far away the sun and moon are thought to be, do you realize how fast they would have to move through space - and the distance traversed - just to "keep up" with the movement of the earth?
Based on the assumption that the earth spins naturally by default, it is utterly unreasonable to think that the earth stopped spinning for 24 hours.
It says nothing directly about the earth moving or not.
Only by implication - and, by comparison with other scriptures - do we arrive at the conclusion that (in this passage) the earth is not moving.