Fix image version

Author: simonkurtz-MSFT

.devcontainer/Dockerfile

@@ -3,7 +3,7 @@
 # syntax=docker/dockerfile:1.4
 
 # Use single-stage build with Python 3.12 (fallback to stable base)
-FROM mcr.microsoft.com/devcontainers/python:0-3.12-bookworm
+FROM mcr.microsoft.com/devcontainers/python:3.12-bookworm
 
 # Set build arguments
 ARG PYTHON_VERSION=3.12