odt test requires specific odt2txt version not present upstream

In 1e3bffc5 the test for odt files updated the dependency on odt2txt to 0.7 ... but this version does not appear to be present upstream or in any distro:

https://repology.org/project/odt2txt/versions

Was this intended to update against odt2txt 0.5-7 in Debian? The tests are currently skipped when building on Debian.

Changing it back to 0.5 in guix fails at least one of the two tests, so obviously something was changed in the versions...