include last record in language-subtag-registry.xml

(cherry picked from commit f854b05013a587a6ea568b32180f5c81de26eeeb)

disable test and document why

disable build breaker test

(cherry picked from commit 73c70f28ba41c7a602d7befde84c5b54187694d7)

document why the test fails and is disabled

(cherry picked from commit 2803e5c1e7112882003c3e2301f8e28f3dc2b6b7)

Change-Id: Iaca0fc9ca12ee672f640be9c639b7b0d0dd3bc10
Reviewed-on: https://gerrit.libreoffice.org/8921
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>