Fix broken devcontainer version

[Vitor Nazário Coelho]

Devcontainer is running with problems on the current version,

Should be updated to a generic version as described here: https://github.com/devcontainers/images/tree/main/src/dotnet

[Christopher Schuchardt]

Here is the real lists https://mcr.microsoft.com/en-us/product/devcontainers/dotnet/tags