[CI] Minor shellcheck cleanup (#8618)
[CI] Minor shellcheck cleanup (#8618)

`# shellcheck disable=SC2039,SC3040` is only if you want it to pass multiple versions, but I figure there's not much reason to keep the old exception for <=0.7.1 in there.
Frenzie/koreader,NiLuJe/koreader,Frenzie/koreader,poire-z/koreader,koreader/koreader,poire-z/koreader,NiLuJe/koreader,koreader/koreader