[New git-credential-manager version] v3.0.0

[github-actions]

https://github.com/git-ecosystem/git-credential-manager/releases/tag/v3.0.0

[dscho]

This is a big one. Moving away, from .NET Framework, using Ahead-Of-Time compilation, using Broker by default... Let's integrate this after it has seen some testing, and definitely after Git for Windows v2.56.0 (which is scheduled for next Monday around evening, UTC time).