Use static classes for job timers (#9940)

Marlin/Marlin.h

@@ -44,12 +44,6 @@
 #include "utility.h"
 #include "serial.h"
 
-#if ENABLED(PRINTCOUNTER)
-  #include "printcounter.h"
-#else
-  #include "stopwatch.h"
-#endif
-
 void idle(
   #if ENABLED(ADVANCED_PAUSE_FEATURE)
     bool no_stepper_sleep = false  // pass true to keep steppers from disabling on timeout
@@ -459,13 +453,6 @@ void report_current_position();
   extern int lpq_len;
 #endif
 
-// Print job timer
-#if ENABLED(PRINTCOUNTER)
-  extern PrintCounter print_job_timer;
-#else
-  extern Stopwatch print_job_timer;
-#endif
-
 // Handling multiple extruders pins
 extern uint8_t active_extruder;