SPARK-3745 - fix check-license to properly download and check jar

for details, see: https://issues.apache.org/jira/browse/SPARK-3745

Author: shane knapp <incomplete@gmail.com>

Closes #2596 from shaneknapp/SPARK-3745 and squashes the following commits:

c95eea9 [shane knapp] SPARK-3745 - fix check-license to properly download and check jar

(cherry picked from commit a01a30927d107a8d9496f749eb9d89eda6dda9d7)
Signed-off-by: Josh Rosen <joshrosen@apache.org>

Conflicts:
	dev/check-license