TEMPE, Ariz. — The season ahead will be demanding, perhaps the most demanding of Yoshinobu Yamamoto’s career. The World Baseball Classic next month. Another six-month MLB regular season. And if the Dodgers reach the heights they expect to reach, another three or four postseason series. All of this after a playoff run in which Yamamoto pitched complete games in consecutive starts and threw the final 2 ⅔ innings of Game 7 of the World Series a day after starting Game 6. As Yamamoto fielded