Remove duplicated clearanceEpsilon

We already get clearance epsilon in the clearance resolver.  Don't
subtract it twice or we end up getting DRC errors

Fixes https://gitlab.com/kicad/code/kicad/-/issues/16879

(cherry picked from commit 10c1072479)

pcbnew/router/pns_item.cpp

@@ -191,9 +191,6 @@ bool ITEM::collideSimple( const ITEM* aHead, const NODE* aNode,
     }
     else
     {
-        if( aCtx && !aCtx->options.m_useClearanceEpsilon )
-            clearanceEpsilon = 0;
-
         clearance = aNode->GetClearance( this, aHead, aCtx ? aCtx->options.m_useClearanceEpsilon
                                                            : false );
     }