Update software on the server via GitHub Actions

[Nircek]

We can add a GitHub Action that sends a packet to the server which would trigger an update process on the server. Currently, the server pulls the commits from GitHub every 15 minutes. If we add a GitHub Action the scheduled pulling is not necessary anymore.

But I recommend waiting for this functionality till #4 because then we could use a secret of a packet data that triggers updating. And it wouldn't have to be tracked in the repo.