Handle files without extensions in Weblate

Originally created by @hefee on #16449 (Redmine)

Here we go - another round of changes for translations-server.

For some days, the cron job fails with:

<code class="text">
Traceback (most recent call last):
  File "/var/lib/weblate/scripts/update-weblate-components.py", line 115, in <module>
    uwg.main(PATH, 'master', None, 'tails/master')
  File "/var/lib/weblate/scripts/update_weblate_git.py", line 392, in main
    if getLang(path) == DEFAULTLANG:
  File "/var/lib/weblate/scripts/update_weblate_git.py", line 56, in getLang
    *name, lang, _ = path.name.split(".")
ValueError: not enough values to unpack (expected at least 2, got 1)
</code>

I fixed that issue at hefee/dev/translation-server branch with 5abd5df9dcb1100e55841dcbfff6b7f42efb5a29 and added some more cleanups to that branch.

Please merge my changes.

Feature Branch: https://salsa.debian.org/hefee/puppet-tails/tree/hefee/dev/translation-server

Parent Task: tails#10034 (closed)