remove cryptonote (unmaintained since 2020) (#3725)

- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3558
- WARNING:awesome_lint.py: cryptonote: last updated -1054 days, 4:04:51.319159 ago, older than 365 days
- installation instructions for Heroku PaaS only, not self-hosted

README.md

@@ -1496,7 +1496,6 @@ A [pastebin](https://en.wikipedia.org/wiki/Pastebin) is a type of online content
 - [0bin](https://github.com/Tygs/0bin) - Client side encrypted pastebin. ([Demo](https://0bin.net/)) `WTFPL` `Python`
 - [bepasty](https://bepasty-server.readthedocs.io/en/latest/) - A pastebin for all kinds of files. ([Source Code](https://github.com/bepasty/bepasty-server)) `BSD-2-Clause` `Python`
 - [bin](https://github.com/w4/bin) - A paste bin that's actually minimalist. `WTFPL/0BSD` `Rust`
-- [cryptonote](https://cryptonote.me/) - Simple open source web application that lets users encrypt and share messages that can only be read once. ([Source Code](https://github.com/alainmeier/cryptonote)) `MIT` `Ruby`
 - [dpaste](https://dpaste.org/) - Simple pastebin with multiple text and code option, with short url result easy to remember. ([Source Code](https://github.com/bartTC/dpaste)) `MIT` `Docker`
 - [Drift](https://github.com/MaxLeiter/drift) - Self-hosted Github Gist clone. ([Demo](https://drift.maxleiter.com/)) `MIT` `Nodejs`
 - [EdPaste](https://github.com/ptnr/EdPaste) - Self-hosted pastebin written in Laravel (PHP Framework). `MIT` `PHP`