Update with newly pulled JSON from the API, as well as some updates to the checks
as we escape the final text now, so we need to reflect that in the test check.

In order for our CI to not fail the appdata check test, we now add a fake
release and a first screenshot into the appdata.

Let us automatically build an Flatpak of the development build.

This includes:
- Using `secret-opts` to include the OAuth Key more securely
- Have distinct artifact names for each job
- Use an one-dimensional build option for platform selection

appstream-util seems to have problems with it

This test has blocked the action for some time but is not a necessity,
so let's disable it until the issues are fully resolved.