Change the JavaScript package manager from `yarn` back to `npm`

.circleci/config.yml

@@ -66,7 +66,7 @@ jobs:
           ruby-version: '3.0'
       - node/install-packages:
           cache-version: v1
-          pkg-manager: yarn
+          pkg-manager: npm
       - run:
           command: ./bin/rails assets:precompile
           name: Precompile assets
@@ -202,8 +202,8 @@ workflows:
       - node/run:
           cache-version: v1
           name: test-webui
-          pkg-manager: yarn
+          pkg-manager: npm
           requires:
             - build
           version: lts
-          yarn-run: test:jest
+          npm-run: test:jest

Dockerfile

@@ -47,20 +47,19 @@ RUN apt-get update && \
 ENV PATH="${PATH}:/opt/ruby/bin:/opt/node/bin"
 
 RUN npm install -g npm@latest && \
-	npm install -g yarn && \
 	gem install bundler && \
 	apt-get update && \
 	apt-get install -y --no-install-recommends git libicu-dev libidn11-dev \
 	libpq-dev shared-mime-info
 
-COPY Gemfile* package.json yarn.lock /opt/mastodon/
+COPY Gemfile* package.json package-lock.json /opt/mastodon/
 
 RUN cd /opt/mastodon && \
   bundle config set --local deployment 'true' && \
   bundle config set --local without 'development test' && \
   bundle config set silence_root_warning true && \
 	bundle install -j"$(nproc)" && \
-	yarn install --pure-lockfile
+	npm install
 
 FROM ubuntu:20.04
 
@@ -113,7 +112,7 @@ USER mastodon
 # Precompile assets
 RUN cd ~ && \
 	OTP_SECRET=precompile_placeholder SECRET_KEY_BASE=precompile_placeholder rails assets:precompile && \
-	yarn cache clean
+	npm cache clean
 
 # Set the work dir and the container entry point
 WORKDIR /opt/mastodon

Procfile.dev

 web: env PORT=3000 RAILS_ENV=development bundle exec puma -C config/puma.rb
 sidekiq: env PORT=3000 RAILS_ENV=development bundle exec sidekiq
-stream: env PORT=4000 yarn run start
+stream: env PORT=4000 npm run start
 webpack: ./bin/webpack-dev-server --listen-host 0.0.0.0