Reduce 'first loop' temperature residency time (#18421)

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

Marlin/src/module/temperature.cpp

           if (!residency_start_ms) {
             // Start the TEMP_RESIDENCY_TIME timer when we reach target temp for the first time.
             if (temp_diff < TEMP_WINDOW) {
-              residency_start_ms = now;
-              if (first_loop) residency_start_ms += SEC_TO_MS(TEMP_RESIDENCY_TIME);
-            }
+              residency_start_ms = now + (first_loop ? SEC_TO_MS(TEMP_RESIDENCY_TIME) / 3 : 0);
           }
           else if (temp_diff > TEMP_HYSTERESIS) {
             // Restart the timer whenever the temperature falls outside the hysteresis.
 
           if (!residency_start_ms) {
             // Start the TEMP_BED_RESIDENCY_TIME timer when we reach target temp for the first time.
-            if (temp_diff < TEMP_BED_WINDOW) {
-              residency_start_ms = now;
-              if (first_loop) residency_start_ms += SEC_TO_MS(TEMP_BED_RESIDENCY_TIME);
-            }
+            if (temp_diff < TEMP_BED_WINDOW)
+              residency_start_ms = now + (first_loop ? SEC_TO_MS(TEMP_BED_RESIDENCY_TIME) / 3 : 0);
           }
           else if (temp_diff > TEMP_BED_HYSTERESIS) {
             // Restart the timer whenever the temperature falls outside the hysteresis.
         }
 
         now = millis();
-        if (ELAPSED(now, next_temp_ms)) { //Print Temp Reading every 1 second while heating up.
+        if (ELAPSED(now, next_temp_ms)) { // Print Temp Reading every 1 second while heating up.
           next_temp_ms = now + 1000UL;
           print_heater_states(active_extruder);
           #if TEMP_CHAMBER_RESIDENCY_TIME > 0
 
           if (!residency_start_ms) {
             // Start the TEMP_CHAMBER_RESIDENCY_TIME timer when we reach target temp for the first time.
-            if (temp_diff < TEMP_CHAMBER_WINDOW) {
-              residency_start_ms = now;
-              if (first_loop) residency_start_ms += SEC_TO_MS(TEMP_CHAMBER_RESIDENCY_TIME);
-            }
+            if (temp_diff < TEMP_CHAMBER_WINDOW)
+              residency_start_ms = now + (first_loop ? SEC_TO_MS(TEMP_CHAMBER_RESIDENCY_TIME) / 3 : 0);
           }
           else if (temp_diff > TEMP_CHAMBER_HYSTERESIS) {
             // Restart the timer whenever the temperature falls outside the hysteresis.