Fix missing include (#19418)

Co-authored-by: ellensp <530024+ellensp@users.noreply.github.com>

Marlin/src/gcode/bedlevel/G35.cpp

@@ -29,6 +29,10 @@
 #include "../../module/probe.h"
 #include "../../feature/bedlevel/bedlevel.h"
 
+#if HAS_MULTI_HOTEND
+  #include "../../module/tool_change.h"
+#endif
+
 #define DEBUG_OUT ENABLED(DEBUG_LEVELING_FEATURE)
 #include "../../core/debug_out.h"