fix: --maxSockets (#363)

Dockerfile

@@ -11,15 +11,17 @@ RUN apk add --no-cache py3-setuptools python3-dev build-base
 # install dependencies
 COPY package.json /app/package.json
 COPY package-lock.json /app/package-lock.json
-RUN npm ci
+# --maxsockets=5 is used to avoid "EMFILE: too many open files" error
+RUN npm ci --maxsockets=5
 
 # build the app
 COPY . /app
 RUN npm run build
 RUN npm run test
 
 # remove devDependencies, keep only used dependencies
-RUN npm ci --only=production
+# --maxsockets=5 is used to avoid "EMFILE: too many open files" error
+RUN npm ci --only=production --maxsockets=5
 
 FROM node:18-alpine