/usr/share/language-tools/del-profile-env-settings is in accountsservice 0.6.43-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 | #!/bin/sh -e
homedir=$1
test -n "$homedir" || exit 1
test -f "$homedir/.profile" && {
    cd "$homedir"
    for var in 'LANGUAGE' 'LANG' 'LC_MESSAGES' 'LC_CTYPE' 'LC_COLLATE'; do
        sed -i "/^export $var=\"[^[:space:]]*\"$/d" .profile
    done
}
 |