docs: fix accidentally duplicated line (#12811)

Fix accidentally duplicated line

Fix accidentally duplicated line

Author: jonathanagustin

docs/pages/getting-started/deployment.mdx

@@ -103,7 +103,6 @@ Our example application is also hosted via Docker [here](https://nextjs-docker-e
 
 ```docker filename="Dockerfile"
 # syntax=docker/dockerfile:1
-# syntax=docker/dockerfile:1
 FROM node:20-alpine AS base
 
 # Install dependencies only when needed