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

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

Marlin/src/module/temperature.cpp

@@ -3100,9 +3100,7 @@ void Temperature::tick() {
           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.
@@ -3227,10 +3225,8 @@ void Temperature::tick() {
 
           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.
@@ -3343,10 +3339,8 @@ void Temperature::tick() {
 
           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.