Fix Skew Correction pre-calculation overflow error

Marlin/src/inc/Conditionals_post.h

@@ -911,7 +911,7 @@
 
   #define _GET_SIDE(a,b,c) (SQRT(2*sq(a)+2*sq(b)-4*sq(c))*0.5)
   #define _SKEW_SIDE(a,b,c) tan(M_PI*0.5-acos((sq(a)-sq(b)-sq(c))/(2*c*b)))
-  #define _SKEW_FACTOR(a,b,c) _SKEW_SIDE(a,_GET_SIDE(a,b,c),c)
+  #define _SKEW_FACTOR(a,b,c) _SKEW_SIDE(float(a),_GET_SIDE(float(a),float(b),float(c)),float(c))
 
   #ifndef XY_SKEW_FACTOR
     constexpr float XY_SKEW_FACTOR = (