Update and simplify deploy image (#253)

- Updates the image to the latest Dart beta.
- Removes Node and NPM as the sites no longer rely on them to build.
- Use the [Firebase standalone binary install](https://firebase.google.com/docs/cli#mac-linux-auto-script) rather than installing it through NPM.

Author: parlough

cloud_build/firebase-ghcli/Dockerfile

@@ -1,4 +1,4 @@
-FROM dart:3.10.0-290.4.beta
+FROM dart:3.11.0-93.2.beta
 
 # Install prerequisite dependencies.
 RUN apt-get update && apt-get install -y curl gpg
@@ -8,13 +8,5 @@ RUN curl -fsSL https://cli.github.com/packages/githubcli-archive-keyring.gpg | g
 RUN echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | tee /etc/apt/sources.list.d/github-cli.list > /dev/null;
 RUN apt update && apt install -y gh;
 
-# Install the latest LTS of Node, which also includes npm.
-RUN mkdir -p /etc/apt/keyrings
-RUN curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
-ENV NODE_MAJOR=22
-RUN echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | tee /etc/apt/sources.list.d/nodesource.list
-RUN apt-get update
-RUN apt-get install nodejs -y
-
 # Install the latest version of firebase-tools globally.
-RUN npm install -g firebase-tools
+RUN curl -sL https://firebase.tools | bash

cloud_build/firebase-ghcli/README.md

@@ -1,7 +1,7 @@
 ## Summary
 
 This directory contains a Dockerfile that provides access to
-Dart, Node/NPM, Firebase CLI tools, and the GitHub CLI.
+Dart, Firebase CLI tools, and the GitHub CLI.
 This image is used to deploy various Dart/Flutter websites to
 Firebase in both production and staging, and is
 also used to comment staging links on GitHub PRs.
@@ -10,7 +10,6 @@ also used to comment staging links on GitHub PRs.
 
 * Dart SDK
 * GitHub CLI
-* Node/NPM
 * Firebase Tools
 
 ## Additional information