🩹 Simplify quick homing feedrate (#23714)

Co-authored-by: Scott Lahteine <github@thinkyhead.com>

Marlin/src/gcode/calibrate/G28.cpp

 
     const int x_axis_home_dir = TOOL_X_HOME_DIR(active_extruder);
 
-    const float mlx = max_length(X_AXIS),
-                mly = max_length(Y_AXIS),
-                mlratio = mlx > mly ? mly / mlx : mlx / mly,
-                fr_mm_s = _MIN(homing_feedrate(X_AXIS), homing_feedrate(Y_AXIS)) * SQRT(sq(mlratio) + 1.0);
+    // Use a higher diagonal feedrate so axes move at homing speed
+    const float minfr = _MIN(homing_feedrate(X_AXIS), homing_feedrate(Y_AXIS)),
+                fr_mm_s = HYPOT(minfr, minfr);
 
     #if ENABLED(SENSORLESS_HOMING)
       sensorless_t stealth_states {
       };
     #endif
 
-    do_blocking_move_to_xy(1.5 * mlx * x_axis_home_dir, 1.5 * mly * Y_HOME_DIR, fr_mm_s);
+    do_blocking_move_to_xy(1.5 * max_length(X_AXIS) * x_axis_home_dir, 1.5 * max_length(Y_AXIS) * Y_HOME_DIR, fr_mm_s);
 
     endstops.validate_homing_move();