Install from nvmrc during devcontainer Dockerfile build (#30603)

.devcontainer/Dockerfile

@@ -1,17 +1,15 @@
 # For details, see https://github.com/devcontainers/images/tree/main/src/ruby
 FROM mcr.microsoft.com/devcontainers/ruby:1-3.3-bookworm
 
-# Update existing node version, keep in sync with .nvmrc
-ARG NODE_VERSION="20"
-RUN . /usr/local/share/nvm/nvm.sh && nvm install ${NODE_VERSION} 2>&1
+# Install node version from .nvmrc
+WORKDIR /app
+COPY .nvmrc .
+RUN /bin/bash --login -i -c "nvm install"
 
 # Install additional OS packages
 RUN apt-get update && \
     export DEBIAN_FRONTEND=noninteractive && \
     apt-get -y install --no-install-recommends libicu-dev libidn11-dev ffmpeg imagemagick libvips42 libpam-dev
 
-# Install global node packages
-RUN . /usr/local/share/nvm/nvm.sh && corepack enable 2>&1
-
 # Move welcome message to where VS Code expects it
-COPY welcome-message.txt /usr/local/etc/vscode-dev-containers/first-run-notice.txt
+COPY .devcontainer/welcome-message.txt /usr/local/etc/vscode-dev-containers/first-run-notice.txt