what is the meaning of this sentence?

It just means the wind dropped until it was hadly noticeable. It's an awkward sentence, it's not well expressed.

The wind slowed, not completely,

but to the point it didn't pay attention to you, you had to pay attention to it.

I suspect that it's the second part that has you confused, Penny.

A strong wind, which this isn't, pays a great deal of "attention" to a person, blowing around, thru them, messing their hair, pulling things from their grasp; figuratively speaking, it pays attention to a body.

Because it was such a light wind, it didn't do the things mentioned above, ie. it was hardly noticeable.