Hair weight

Hi. You could manually remove unnecessary paint in Edit mode, but in your case it is better to transfer it from the body. The clavicles are painted in the wrong place.
Your mesh is unnecessary high poly, there is no need to crank up subdivisions this much, it takes forever to load
Another thing you should do is transfer a uv_1 map. The hair will not morph properly.
Also select everything and use Mesh - Clean up - Delete loose, there are loose vertices.
New package and blend files