Change in coreboot[master]: util/gitconfig/test: Add shellcheck test

[build bot (Jenkins) (Code Review)]

build bot (Jenkins) has posted comments on this change. ( https://review.coreboot.org/23283 )

Change subject: util/gitconfig/test: Add shellcheck test
......................................................................

Patch Set 4: Verified+1

Build Successful

https://qa.coreboot.org/job/coreboot-checkpatch/22748/ : SUCCESS

https://qa.coreboot.org/job/coreboot-gerrit/68312/ : SUCCESS