Post a message to Discord on failed build

[Riscky]

Since the builds on the master branch correspond to deploys, it would be nice to know when a build fails.
We should post a message to Discord on a failed build.
There is an example of how to run a build step on failure here: https://docs.github.com/en/actions/learn-github-actions/expressions#failure

[Riscky]

We currently get very annoying emails, so we should also disable those probably