remove Ironfunctions (unmaintained) (#3520)

- unmaintained since 2018
- no activity in issues tracker
- unanswered issue about maintenance https://github.com/iron-io/functions/issues/715
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -1797,7 +1797,6 @@ Software for easy installation, management and configuration of self-hosted serv
 - [Appwrite](https://appwrite.io) - End to end backend server for web, native, and mobile developers 🚀. ([Source Code](https://github.com/appwrite/appwrite)) `BSD-3-Clause` `PHP`
 - [Coolify](https://coolify.io/) - An open-source & self-hostable Heroku / Netlify alternative (and even more). ([Demo](https://demo.coolify.io/), [Source Code](https://github.com/coollabsio/coolify)) `Apache-2.0` `Docker`
 - [fx](https://github.com/metrue/fx) - A tool to help you do Function as a Service with painless on your own servers. `MIT` `Go`
-- [IronFunctions](https://github.com/iron-io/functions) - The serverless microservices platform by [iron.io](https://www.iron.io/). `Apache-2.0` `Go`
 - [LocalStack](https://localstack.cloud/) - LocalStack is a fully functional local AWS cloud stack. This includes Lambda for serverless computation. ([Source Code](https://github.com/localstack/localstack)) `Apache-2.0` `Python/Other`
 - [Nhost](https://nhost.io/) - The Open Source Firebase Alternative with GraphQL. Get a database and backend configured and ready in minutes. ([Source Code](https://github.com/nhost/nhost)) `MIT` `Docker/Nodejs/Go`
 - [OpenFaaS](https://www.openfaas.com/) - Serverless Functions Made Simple for Docker & Kubernetes. ([Source Code](https://github.com/openfaas/faas)) `MIT` `Go`