Mar. 7—JUPITER, Fla. — A pair of home runs from outfielder Jordan Walker and designated hitter Matt Carpenter weren’t enough for the Cardinals to overcome an early deficit in their Grapefruit League game on Thursday against the Houston Astros. The Cardinals fell 6-3 to the Astros at Roger Dean Stadium after veteran right-hander Kyle Gibson gave up four first-inning runs to an Astros lineup that…