- fixes variant name

Signed-off-by: Vincent Biret <vibiret@microsoft.com>

.devcontainer/Dockerfile

@@ -1,7 +1,7 @@
 # See here for image contents: https://github.com/microsoft/vscode-dev-containers/blob/v0.245.2/containers/dotnet/.devcontainer/Dockerfile
 
 ARG VARIANT="8.0-bookworm-slim"
-FROM mcr.microsoft.com/vscode/devcontainers/dotnet:0-${VARIANT}
+FROM mcr.microsoft.com/vscode/devcontainers/dotnet:${VARIANT}
 
 # [Choice] Node.js version: none, lts/*, 16, 14, 12, 10
 ARG NODE_VERSION="none"