In commit “ci: export LC_ALL” (04eb50505be5700b374d552aaa814422b41ebc33)
I don’t think the config fragments like ci/configs/default.sh should have hashbangs or export LC_ALL because they aren’t marked executable and aren’t designed to be run as standalone scripts. (They only set variables and I wouldn’t want to encourage them to do anything more than that.)
To avoid the lint error, I’d suggest renaming the config files to ci/configs/*.bash instead. This would also be nice because it would indicate that the config files must use bash, not some other variant of shell script. (Note that renaming would also require updating .github/workflows/ci.yml and ci/README.md)