Update to .NET 10 and move to Forgejo, still some CI and README cleanup to do but going to do that after testing the release CI

Reviewed-on: https://git.unfrl.com/Unfrl/dug/pulls/1
Co-authored-by: MattInternet <matt@kaijucode.com>
Co-committed-by: MattInternet <matt@kaijucode.com>