chore: remove unused demo dockfile

scripts/Dockerfile.demo

@@ -1,41 +0,0 @@
-# Build frontend dist.
-FROM node:20-alpine AS frontend
-WORKDIR /frontend-build
-
-COPY . .
-
-WORKDIR /frontend-build/web
-
-RUN npm install -g pnpm
-RUN pnpm i --frozen-lockfile
-RUN pnpm build
-
-# Build backend exec file.
-FROM golang:1.24-alpine AS backend
-WORKDIR /backend-build
-
-COPY . .
-COPY --from=frontend /frontend-build/web/dist /backend-build/server/router/frontend/dist
-
-RUN go build -o memos ./bin/memos/main.go
-
-# Make workspace with above generated files.
-FROM alpine:latest AS monolithic
-WORKDIR /usr/local/memos
-
-RUN apk add --no-cache tzdata
-ENV TZ="UTC"
-
-COPY --from=backend /backend-build/memos /usr/local/memos/
-COPY ./scripts/entrypoint.sh /usr/local/memos/
-
-EXPOSE 5230
-
-# Directory to store the data, which can be referenced as the mounting point.
-RUN mkdir -p /var/opt/memos
-VOLUME /var/opt/memos
-
-ENV MEMOS_MODE="prod"
-ENV MEMOS_PORT="5230"
-
-ENTRYPOINT ["./entrypoint.sh", "./memos"]