CLDR-18367 Revert wide formatted Sunday (#4511)

Author: AEApple

common/main/fi.xml

@@ -2284,7 +2284,7 @@ Warnings: All cp values have U+FE0F characters removed. See /annotationsDerived/
 							<day type="sat">↑↑↑</day>
 						</dayWidth>
 						<dayWidth type="wide">
-							<day type="sun">sunnuntai</day>
+							<day type="sun">sunnuntaina</day>
 							<day type="mon">maanantaina</day>
 							<day type="tue">tiistaina</day>
 							<day type="wed">keskiviikkona</day>