Fixes plants dying in soil and open hydroponics trays (#21679)

The light for the plants was being counted as double their value,
meaning a light level of 4 would be considered light level 8 by the
plant, thus being vastly outside its preferred range

code/modules/hydroponics/trays/tray_process.dm

@@ -104,7 +104,7 @@
 	// Handle light requirements for upcoming logic.
 	var/light_supplied
 	if(!closed_system)
-		light_supplied = T.get_lumcount(0, 3) * 10
+		light_supplied = T.get_lumcount(0, 3) * 5
 	else
 		light_supplied = tray_light
 

html/changelogs/ReopenTheGarden.yml

@@ -0,0 +1,6 @@
+author: TheGreyWolf
+
+delete-after: True
+
+changes:
+  - bugfix: "Fixes the gardening plots and open hydroponics trays being unable to grow plants."