fix(db-functions): avoid git asking for credentials for unknown repos

Use GIT_TERMINAL_PROMPT=0 to enforce Git not asking for any prompts or
credentials. GitLab does not return none existing repositories but
instead prompts for credentials to avoid side channel information leaks.
However, we explicitly do not want to get any such prompts, instead we
fail gracefully.

db-functions-git

@@ -62,6 +62,10 @@ fetch_pkgbuild() {
 	project_path=$(gitlab_project_name_to_path "${pkgbase}")
 	src="${GIT_PACKAGING_REPOS_URL}/${project_path}.git"
 	target="${GIT_PACKAGES_CACHE}/${pkgbase}"
+
+	# avoid git operations asking for terminal input
+	export GIT_TERMINAL_PROMPT=0
+
 	if [[ ! -d $target ]]; then
 		if ! arch_git -c core.sharedRepository=group clone --origin origin --bare --mirror "${src}" "${target}"; then
 			return 1