Move to Dockerfile (microsoft/vscode-remote-release#8994)

.devcontainer/Dockerfile

@@ -8,6 +8,7 @@ RUN git config --system codespaces-theme.hide-status 1
 USER node
 RUN npm install -g node-gyp
 RUN YARN_CACHE="$(yarn cache dir)" && rm -rf "$YARN_CACHE" && ln -s /vscode-dev/yarn-cache "$YARN_CACHE"
+RUN echo 'export DISPLAY="${DISPLAY:-:1}"' | tee -a ~/.bashrc >> ~/.zshrc
 
 USER root
 CMD chown node:node /vscode-dev && sudo -u node mkdir -p /vscode-dev/yarn-cache && sleep inf

.devcontainer/post-create.sh

@@ -1,6 +1,4 @@
 #!/bin/sh
 
-echo 'export DISPLAY="${DISPLAY:-:1}"' | tee -a ~/.bashrc >> ~/.zshrc
-
 yarn install --network-timeout 180000
 yarn electron