Run the Action for updating the POT file after any change

[lslezak]

Problem

• The Weblate server quite often reports conflicts in the translations. When a conflict is detected then the translation repository is locked and the translators cannot do any changes. The reason is to avoid translating possibly outdated texts and causing even more conflicts and also to avoid wasting translator's time .
• The conflicts need to be resolved manually which is a bit annoying.
• Originally I wanted to avoid spamming the Weblate with too often changes so the translations were sent from Agama to Weblate only once a day. But that seems to cause conflicts quite often as the Agama sources might change in the meantime.

Solution

• Run the POT update action after every change (merge) in the master branch
• To minimize the amount of runs run the action only when a source file is modified. When changing only documentation, unit tests, configuration files, etc... we can skip this action.
• Moreover the action itself checks if there is any change in the translations and if not then it does not update Weblate, this also decreases the traffic.

Notes

• Let's see how this helps, we can tweak it later again if needed