Hello there,
You can’t remove the view distance limit on the fly. This requires a recompile of the map-source to be done.
The effect you are presenting is achieved by the “_farplanedist” key-value pair and is a setting of the worldspawn entity. These settings are compiled into the *.bsp during compile stage, so in order to change it, you will have to recompile the map.
[Reference: Chruker]
Usually, this effect is introduced into a map to get higher FPS in an open area, so maybe removing it, could bring some negative effects with it.
Your best bet is to contact the mapper for the source-file (unless you already have it) and try to recompile the map yourself.