Use built-in bun user from oven/bun image instead of creating custom user

@@ -2,17 +2,13 @@ FROM oven/bun:1-alpineENV NEXT_TELEMETRY_DISABLED=1RUN addgroup -S -g 1000 app && \    adduser -S -h /app -s /sbin/nologin -u 1000 -G app app && \    chown -R app:app /appWORKDIR /home/bun/appWORKDIR /appCOPY package.json bun.lock /app/COPY package.json bun.lock ./RUN bun install --frozen-lockfileCOPY . .RUN bun run next:buildUSER app:appUSER bun