remove bbpress (unmaintained)

- unmaintained since march 2022 https://bbpress.trac.wordpress.org/log/trunk
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -516,7 +516,6 @@ Simple deployment of [E-mail](https://en.wikipedia.org/wiki/Email) servers, e.g.
 - [Akkoma](https://akkoma.social/) - Federated microblogging server with Mastodon, GNU social, and ActivityPub compatibility. ([Source Code](https://akkoma.dev/AkkomaGang/akkoma)) `AGPL-3.0` `Elixir`
 - [Anahita](https://www.getanahita.com/) - Open Source Social Networking Framework and Platform. ([Source Code](https://github.com/anahitasocial/anahita)) `GPL-3.0` `PHP`
 - [AsmBB](https://board.asm32.info) - A fast, SQLite-powered forum engine written in ASM. ([Source Code](https://asm32.info/fossil/asmbb/index)) `EUPL-1.2` `Assembly`
-- [bbPress](https://bbpress.org/) - Forum software with a twist from the creators of WordPress. Easily setup discussion forums inside your WordPress.org powered site. ([Source Code](https://bbpress.trac.wordpress.org/browser/trunk)) `GPL-2.0` `PHP`
 - [Bibliogram](https://bibliogram.art) `⚠` - An alternative front-end for Instagram. ([Source Code](https://sr.ht/~cadence/bibliogram/)) `AGPL-3.0` `Nodejs`
 - [Bootcamp](https://trybootcamp.vitorfs.com) - Enterprise social network. ([Source Code](https://github.com/vitorfs/bootcamp)) `MIT` `Python`
 - [Buddycloud](http://buddycloud.com/) - Tools, libraries, services and a community to build user-to-user, group and social messaging into your app. Saves time. Scales up. Supports you. ([Source Code](https://github.com/buddycloud)) `Apache-2.0` `Java`