devDependenciesが入り込まない様に修正

infra/docker/Dockerfile

@@ -10,8 +10,6 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
 	&& apt-get install -yqq --no-install-recommends \
 	python3
 
-RUN corepack enable
-
 WORKDIR /jetdisc
 
 COPY --link ["pnpm-lock.yaml", "package.json", "./"]
@@ -24,6 +22,14 @@ COPY --link . ./
 ARG NODE_ENV=production
 RUN pnpm build
 
+# ビルド成果物だけど取り扱うレイヤ
+FROM node:${NODE_VERSION} AS node-lib
+
+WORKDIR /jetdisc
+
+COPY --link ["pnpm-lock.yaml", "package.json", "./"]
+RUN pnpm i --frozen-lockfile --prod
+
 FROM node:${NODE_VERSION}-slim AS runner
 
 ARG UID="991"
@@ -43,7 +49,7 @@ RUN apt-get update \
 USER jetdisc
 WORKDIR /jetdisc
 
-COPY --chown=jetdisc:jetdisc --from=builder /jetdisc/node_modules ./node_modules
+COPY --chown=jetdisc:node-lib --from=builder /jetdisc/node_modules ./node_modules
 COPY --chown=jetdisc:jetdisc --from=builder /jetdisc/built ./built
 COPY --chown=jetdisc:jetdisc . ./