Use pnpm and node20 in docker

Dockerfile

@@ -1,11 +1,13 @@
-FROM node:18-alpine
-RUN yarn set version stable
-
-RUN apk update && apk add --no-cache bash
+FROM node:20-alpine
+ENV PNPM_HOME="/pnpm"
+ENV PATH="$PNPM_HOME:$PATH"
+RUN corepack enable
+RUN apk add --no-cache bash
 WORKDIR /app
-COPY package.json yarn.lock .yarnrc.yml ./
-RUN yarn install
+
+COPY package.json pnpm-lock.yaml ./
+RUN pnpm install --prod --frozen-lockfile
 COPY . .
 
-ENTRYPOINT ["yarn"]
+ENTRYPOINT ["pnpm"]
 CMD ["start"]