Deprecate `WithNuget`

Merged
TI
1y ago
+78-24

The feature cannot be supported for dotnet run app.cs (#2754), and complicates things like #2508.
Better to deprecate it for the next patch version, then remove it later in the next minor version.
The feature has been fully subsumed by the much more powerful MsBuildArguments (the only downside is user's csproj will have more lines).

Added Job.WithMsBuildArguments extension to simplify usage.