It’s by design. Apparently the devs consider this a feature for some weird reason. You can’t change it unless you install a version of HA without the supervisor.
If you block it you can run into even worse problems because of another bug in the DNS configuration, which is also considered a feature / non-issue by the devs. See this issue, or many other similar ones.
Possible solutions are to either ignore the ridiculous amount of version / online checks or to install a version of HA without the supervisor.
I don’t get how this is a feature? Isn’t HA all about freedom to remove your devices from the cloud, HA shouldn’t be this depended on the internet and phoning “home”.