Welcome to the forum!
I'm afraid there isn't a way to do this. But you can play back your animations with a different time scale. See spine-unity Runtime Documentation: SkeletonAnimation Component for more detail on this subject.
If you want to preview the animations in Spine with a timescale of 1.25 you can do so in the Preview
view. Just set Speed
to 125
.
Otherwise you will need to scale your animations. This can be done by box selecting the overview row (top row)in the dopesheet while having nothing selected, and then dragging the edge of the box to scale it.
I hope this helps!