chore(devcontainer): optimize container build for ci

.devcontainer/Dockerfile

@@ -1,6 +1,7 @@
 # Update the NODE_VERSION arg in docker-compose.yml to pick a Node version: 18, 16, 14
+ARG BUILD_TARGET=dev
 ARG NODE_VERSION=24
-FROM mcr.microsoft.com/devcontainers/javascript-node:${NODE_VERSION} AS dev
+FROM mcr.microsoft.com/devcontainers/javascript-node:${NODE_VERSION} AS base
 
 # VARIANT can be either 'hugo' for the standard version or 'hugo_extended' for the extended version.
 ARG HUGO_VARIANT=hugo
@@ -13,6 +14,8 @@ RUN export ARCH=$(uname -m | sed -e 's/aarch64/arm64/' -e 's/x86_64/amd64/') \
     && dpkg -i ${HUGO_VARIANT}_${HUGO_VERSION}_linux-${ARCH}.deb \
     && rm ${HUGO_VARIANT}_${HUGO_VERSION}_linux-${ARCH}.deb
 
+FROM base as dev
+
 # Install gh cli repo
 RUN sudo mkdir -p -m 755 /etc/apt/keyrings \
 	&& out=$(mktemp) && wget -nv -O$out https://cli.github.com/packages/githubcli-archive-keyring.gpg \
@@ -52,4 +55,6 @@ VOLUME [ "/home/node/.zsh" ]
 # Hugo dev server port
 EXPOSE 1313
 
+FROM ${BUILD_TARGET}
+
 USER node

.devcontainer/devcontainer.json

@@ -21,7 +21,8 @@
 			// Rebuild the container if it already exists to update.
 			"VERSION": "latest",
 			// Update NODE_VERSION to pick the Node.js version: 12, 14
-			"NODE_VERSION": "24"
+			"NODE_VERSION": "24",
+			"BUILD_TARGET": "${localEnv:BUILD_TARGET:dev}"
 		}
 	},
 	"features": {

.github/workflows/main.yaml

@@ -29,6 +29,7 @@ permissions:
 env:
   IMAGE_NAME: ghcr.io/${{ github.repository }}/devcontainer
   IMAGE_TAG: ${{ github.event_name == 'pull_request' && format('pr-{0}', github.event.pull_request.number) || 'latest' }}
+  BUILD_TARGET: base
 
 jobs:
   prepare: