Just tell your players they can’t choose spell casting classes

In other words, remove those classes from your game.

To play without magic and combat, you'd need to ignore most of chapter 2 (only human); most of chapter 3 (only 3 classes get first level non-combat, non-magic features, and two are spellcasters); half of chapter 5 (no weapons or armour); half of chapter 6 (no combat feats); chapters 9, 10 and 11; and most of the appendices. I did a quick check, and you'd use less than 100 pages out of the 318 in the rulebook.

So much for "literally zero".