Remove UK government API catalogue, it's broken

UK government API catalogue returns http code 404 when accessed

README.md

@@ -1092,7 +1092,6 @@ API | Description | Auth | HTTPS | CORS |
 | [Open Government, West Australia](https://data.wa.gov.au/) | West Australia Open Data | No | Yes | Unknown |
 | [Represent by Open North](https://represent.opennorth.ca/) | Find Canadian Government Representatives | No | Yes | Unknown |
 | [UK Companies House](https://developer.company-information.service.gov.uk/) | UK Companies House Data from the UK government | `OAuth` | Yes | Unknown |
-| [UK government API catalogue](https://alphagov.github.io/api-catalogue) | APIs from UK government organisations | No | Yes | Unknown |
 | [US Presidential Election Data by TogaTech](https://uselection.togatech.org/api/) | Basic candidate data and live electoral vote counts for top two parties in US presidential election | No | Yes | No |
 | [USA.gov](https://www.usa.gov/developer) | Authoritative information on U.S. programs, events, services and more | `apiKey` | Yes | Unknown |
 | [USAspending.gov](https://api.usaspending.gov/) | US federal spending data | No | Yes | Unknown |