Revert the SHAPE_ARC::Collide() part.

The arc width appears to be handled elsewhere (at least in
the test suite).

Fixes https://gitlab.com/kicad/code/kicad/-/issues/16951

libs/kimath/src/geometry/shape_arc.cpp

@@ -244,7 +244,6 @@ bool SHAPE_ARC::Collide( const SEG& aSeg, int aClearance, int* aActual, VECTOR2I
     if( aSeg.A == aSeg.B )
         return Collide( aSeg.A, aClearance, aActual, aLocation );
 
-    int      minDist = aClearance + m_width / 2;
     VECTOR2I center = GetCenter();
     CIRCLE   circle( center, GetRadius() );
 
@@ -264,7 +263,7 @@ bool SHAPE_ARC::Collide( const SEG& aSeg, int aClearance, int* aActual, VECTOR2I
 
     for( const VECTOR2I& candidate : candidatePts )
     {
-        if( Collide( candidate, minDist, aActual, aLocation ) )
+        if( Collide( candidate, aClearance, aActual, aLocation ) )
             return true;
     }