We make several calls to `os/user`, which uses CGO and means
cross-compilation is not possible. This replaces `os/user` with the
`luser` package, which is a drop-in replacement which does not use `CGO`
* Make `async:true` the default for `invoke` calls (#3750)
* Switch away from native grpc impl. (#3728)
* Remove usage of the 'deasync' library from @pulumi/pulumi. (#3752)
* Only retry as long as we get unavailable back. Anything else continues. (#3769)
* Handle all errors for now. (#3781)
* Do not assume --yes was present when using pulumi in non-interactive mode (#3793)
* Upgrade all paths for sdk and pkg to v2
* Backport C# invoke classes and other recent gen changes (#4288)
Adjust C# generation
* Replace IDeployment with a sealed class (#4318)
Replace IDeployment with a sealed class
* .NET: default to args subtype rather than Args.Empty (#4320)
* Adding system namespace for Dotnet code gen
This is required for using Obsolute attributes for deprecations
```
Iam/InstanceProfile.cs(142,10): error CS0246: The type or namespace name 'ObsoleteAttribute' could not be found (are you missing a using directive or an assembly reference?) [/Users/stack72/code/go/src/github.com/pulumi/pulumi-aws/sdk/dotnet/Pulumi.Aws.csproj]
Iam/InstanceProfile.cs(142,10): error CS0246: The type or namespace name 'Obsolete' could not be found (are you missing a using directive or an assembly reference?) [/Users/stack72/code/go/src/github.com/pulumi/pulumi-aws/sdk/dotnet/Pulumi.Aws.csproj]
```
* Fix the nullability of config type properties in C# codegen (#4379)
This was still in pkg and wasn't accessible from the scripts location.
This code should be in the go/common location of sdk so that it can be
accessed from within our build scripts
Without this change, we were not able to get access to the Version number
for Python and none of our Python builds have been publishing binaries
