xxx36_Holder two out of four holes are of wrong size

Holes for mounting EBB36 in `user_mods/JosAr/G2_Umbilical_for_z_chain/STL/xxx36_Holder.stl` are too large for M3 screws to be directly tapped into them and too small for heat set inserts.

Open user_mods/JosAr/G2_Umbilical_for_z_chain/STL/xxx36_Holder.stl and inspect the four EBB36 mounting holes, focusing on the two reported as incorrect. Confirm whether the intended fit is direct M3 tapping or heat-set inserts, then update the model and verify that all four holes support the intended mounting method.

Written by the indexing model from the issue text.