⚡️ G12 - Only require used axes to be homed (#23422)

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

Marlin/src/gcode/feature/clean/G12.cpp

  */
 void GcodeSuite::G12() {
   // Don't allow nozzle cleaning without homing first
-  if (homing_needed_error()) return;
+  if (homing_needed_error(linear_bits & ~TERN0(NOZZLE_CLEAN_NO_Z, Z_AXIS) & ~TERN0(NOZZLE_CLEAN_NO_Y, Y_AXIS)))
+    return;
 
   #ifdef WIPE_SEQUENCE_COMMANDS
     if (!parser.seen_any()) {

Marlin/src/module/motion.h

   constexpr linear_axis_bits_t axis_homed = linear_bits, axis_trusted = linear_bits; // Zero-endstop machines are always homed and trusted
   inline void homeaxis(const AxisEnum axis)           {}
   inline void set_axis_never_homed(const AxisEnum)    {}
-  inline linear_axis_bits_t axes_should_home(linear_axis_bits_t=linear_bits) { return false; }
+  inline linear_axis_bits_t axes_should_home(linear_axis_bits_t=linear_bits) { return 0; }
   inline bool homing_needed_error(linear_axis_bits_t=linear_bits) { return false; }
   inline void set_axis_unhomed(const AxisEnum axis)   {}
   inline void set_axis_untrusted(const AxisEnum axis) {}