chore(tests): throw ElggUpgrade exceptions untranslated to get rid of library dependencies

ElggUpgrade was translating its exception messages which required
ElggUpgradeTest to include the languages library. Use of the libraries
is prone to cause dependency chains, so it's better not to translate
the exceptions at all for now.

Fixes #7276
Merge pull request #7277 from juho-jaakkola/dont_translate_upgrade_exceptions

chore(tests): throw ElggUpgrade exceptions untranslated to get rid of library dependencies