[MM-28948] Fix errcheck linter issues in import_functions.go (#30615)

Co-authored-by: Claude <noreply@anthropic.com>

server/.golangci.yml

@@ -94,7 +94,6 @@ issues:
         channels/app/file.go|\
         channels/app/file_test.go|\
         channels/app/helper_test.go|\
-        channels/app/import_functions.go|\
         channels/app/permissions_test.go|\
         channels/app/platform/helper_test.go|\
         channels/app/platform/license.go|\