When using central package versions, package source mapping for more than one source is required

[kzu]

See https://learn.microsoft.com/en-us/nuget/consume-packages/package-source-mapping.

If you don't map via nuget.config, you get warnings like:

 warning NU1507: There are 2 package sources defined in your configuration. When using central package management, please map your package sources with package source mapping (https://aka.ms/nuget-package-source-mapping) or specify a single package source. The following sources are defined: https://api.nuget.org/v3/index.json, https://pkg.kzu.io/index.json ```