remove Clink (unmaintained since 2021, certificate expired) (#3837)

- https://git.swurl.xyz/swirl/clink : HTTPSConnectionPool(host='git.swurl.xyz', port=443): Max retries exceeded with url: /swirl/clink (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate has expired (_ssl.c:997)')))
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3558

README.md

@@ -2030,7 +2030,6 @@ _Related: [Task Management & To-do Lists](#task-management--to-do-lists), [Softw
 Before hosting one, please see [shortcomings](https://en.wikipedia.org/wiki/URL_shortening#Shortcomings) of URL shorteners.
 
 - [Blink](https://docs.blink.rest) - Easy-to-host, SSO-integrated, CDN-powered link shortener (+decoupled analytics) for teams. ([Source Code](https://github.com/JaneJeon/blink)) `AGPL-3.0` `Nodejs`
-- [Clink](https://short.swurl.xyz/) - Dead-simple, super minimal URL shortener in C. ([Source Code](https://git.swurl.xyz/swirl/clink)) `AGPL-3.0` `C`
 - [Easyshortener](https://github.com/easypanel-community/easyshortener) - A simple URL shortener. `MIT` `PHP/Nodejs/Docker`
 - [goshorly](https://gitea.hackmi.ch/Phil/goshorly) - An easy self-hosted Link shortener in Golang. `MIT` `Go`
 - [Kutt](https://kutt.it) - A modern URL shortener with support for custom domains. ([Source Code](https://github.com/thedevs-network/kutt)) `MIT` `Nodejs`