Adjust West Valley weights

[pmpowers-usgs]

The dip variant weights in the West Valley geodetic models have been halved (0.1, 0.3, and 0.1; 0.05 total weight in each geodetic model) suggesting this perhaps was slated to be considered a low probability of occurrence fault (see this issue for 2017). However, the change was never propagated through to the geologic model.