Migrate off Vercel and to OpenNext/AWS

[marcoacierno]

### Tasks
- [ ] Confirm https://open-next.js.org/ is the best option (Support for ISG / Server-side rendered pages and @vercel/og?)
- [ ] Confirm AWS costs and how the infrastructure will be setup - Using https://sst.dev/? I would prefer terraform if SST is just an alternative to terraform
- [ ] Remove vercel banner from the website footer
- [ ] Remove vercel banner from the readme repo

We also use vercel for https://github.com/pythonitalia/community BE, FE and the Postgres database are all in Vercel. It requires a bigger migration. We might consider moving it into this BE.

[marcoacierno]

While it has some shortcomings, AWS amplify might be a good alternative too: https://aws.amazon.com/amplify/

Pricing-wise I am not convinced: https://aws.amazon.com/amplify/pricing/

[patrick91]

I'm still waiting to hear from Vercel if we can keep the sponsorship 😊

[marcoacierno]

https://coolify.io/ https://coolify.io/docs/installation

[marcoacierno]

We ended up migrating to ECS for Production and still use Vercel Hobby plan for PR previews