Avoid Microsoft.Bcl.* dependencies

[ViktorHofer]

It would be great if this repository could add modern .NET TFMs to projects that only target .NET Standard to avoid bringing Microsoft.Bcl.* packages into the dependency graph. Adding those also has a couple of other benefits: optimized IL, analyzers, etc.

We got hit by #7589 on a .NET 10 only app, which made me open this issue.

cc @tarekgh

[tarekgh]

CC @rokonec