Update image (microsoft#55)

Author: bamurtaugh

.devcontainer/Dockerfile

@@ -1,7 +1,7 @@
 # See here for image contents: https://github.com/microsoft/vscode-dev-containers/blob/v0.202.3/containers/python-3/.devcontainer/base.Dockerfile
 # [Choice] Python version (use -bullseye variants on local arm64/Apple Silicon): 3, 3.9, 3.8, 3.7, 3.6, 3-bullseye, 3.9-bullseye, 3.8-bullseye, 3.7-bullseye, 3.6-bullseye, 3-buster, 3.9-buster, 3.8-buster, 3.7-buster, 3.6-buster
 ARG VARIANT=3-bullseye
-FROM mcr.microsoft.com/vscode/devcontainers/python:0-${VARIANT}
+FROM mcr.microsoft.com/devcontainers/python:0-${VARIANT}
 
 # [Optional] Allow the vscode user to pip install globally w/o sudo
 ENV PIP_TARGET=/usr/local/pip-global