Remove Forgejo instances (#172)

Forgejo is generally considered a separate project from Gitea and
no longer considered a soft fork. A soft fork can be treated like a
server running a slightly modified version. A hard fork cannot.

Reviewed-on: https://gitea.com/gitea/awesome-gitea/pulls/172
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: delvh <dev.lh@web.de>
Co-authored-by: Charles <c4a@monocles.eu>
Co-committed-by: Charles <c4a@monocles.eu>

README.md

@@ -126,11 +126,8 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 
 ### Open Registration
 
-- [Codeberg](https://codeberg.org/Codeberg) - Non-Profit Collaboration Community for Free and Open Source Projects (formerly known under its working title teahub.io).
-- [Disroot](https://git.disroot.org/) - Aims to change the way people are used to interact on the web.
 - [OpenDev](https://opendev.org/) - A space for collaborative Open Source software development.
 - [RadioRepo](https://repo.radio/) - The home of software development for the Amateur Radio Community.
-- [~vern gitea](https://git.vern.cc/) - A gitea instance for free software hackers
 
 ### For internal use
 
@@ -138,7 +135,6 @@ A curated list of awesome projects related to Gitea and its soft-fork instances.
 - [openSUSE](https://src.opensuse.org/) - openSUSE Gitea
 - [FSFE](https://git.fsfe.org/) - Git @ Free Software Foundation Europe
 - [PSES](https://git.passageenseine.fr/pses) - Git @ Pas Sage en Seine.
-- [Sum7](https://dev.sum7.eu/) - A hoster to support decentralized services. A step away from big cloud services.
 
 ## Packages