Hi folks, I ran a github workflow with "docker://pulumi/actions" and I got some errors when building my pulumi project with the latest version of NetCore sdk (3.1.x) it is not supported by pulumi actions container ?

That is correct. As James mentioned, our longer-term plan is to just split the

pulumi/pulumi

container into multiple, smaller, ones with specific language runtime versions. But for now, the canonical

pulumi/pulumi

one only installs the .NET Core 3.0 SDK.