project management: remove link to awesome-sysadmin (#3831)

- awesome-sysadmin's `Code Review` section has been merged with `Software Development - Project Management`.
- ref. https://github.com/awesome-foss/awesome-sysadmin/pull/488

README.md

@@ -1871,8 +1871,6 @@ Tools and software for [software project management](https://en.wikipedia.org/wi
 
 _Related: [Ticketing](#ticketing), [Task Management & To-do Lists](#task-management--to-do-lists)_
 
-_See also: [awesome-sysadmin/Code Review](https://github.com/awesome-foss/awesome-sysadmin#code-review)_
-
 - [Bonobo Git Server](https://bonobogitserver.com/) - Set up your own self hosted git server on IIS for Windows. Manage users and have full control over your repositories with a nice user friendly graphical interface. ([Source Code](https://github.com/jakubgarfield/Bonobo-Git-Server)) `MIT` `C#`
 - [Cgit](https://git.zx2c4.com/cgit/about/) - A fast lightweight web interface for git repositories. ([Source Code](https://git.zx2c4.com/cgit/tree/)) `GPL-2.0` `C`
 - [Fossil](https://www.fossil-scm.org/index.html/doc/trunk/www/index.wiki) - Distributed version control system featuring wiki and bug tracker. `BSD-2-Clause-FreeBSD` `C`