Add mikroORM to external package list (#50487)

### What?

Adds mikroORM to external package list

### Why?

To prevent developers using
[MedusaJS](https://github.com/medusajs/medusa) modules with NextJS from
having to add this in their next config.

---------

Co-authored-by: JJ Kasper <jj@jjsweb.site>

packages/next/src/lib/server-external-packages.json

@@ -1,11 +1,13 @@
 [
   "@blockfrost/blockfrost-js",
   "@jpg-store/lucid-cardano",
+  "@mikro-orm/core",
+  "@mikro-orm/knex",
   "@prisma/client",
-  "@vercel/og",
   "@sentry/nextjs",
   "@sentry/node",
   "@swc/core",
+  "@vercel/og",
   "argon2",
   "autoprefixer",
   "aws-crt",
@@ -25,10 +27,10 @@
   "next-mdx-remote",
   "next-seo",
   "pg",
+  "playwright",
   "postcss",
   "prettier",
   "prisma",
-  "playwright",
   "puppeteer",
   "rimraf",
   "sharp",