fix: remove dead API links and update IUCN URL in Animals section

Remove 3 broken entries that return errors and are no longer accessible:
- AdoptAPet (https://adoptapet.com/public/apis/pet_list.html) -> 403
- Cataas (https://cataas.com/) -> 404
- Petfinder (https://www.petfinder.com/developers/) -> 403

Update IUCN to the working HTTPS URL (was HTTP, now returns 403):
- Old: http://apiv3.iucnredlist.org/api/v3/docs
- New: https://www.iucnredlist.org/en

README.md

@@ -127,11 +127,11 @@ Join our [Discord server](https://discord.com/invite/hgjA78638n/?utm_source=Gith
 ### Animals
 API | Description | Auth | HTTPS | CORS 
 |:---|:---|:---|:---|:---|
-| [AdoptAPet](https://www.adoptapet.com/public/apis/pet_list.html) | Resource to help get pets adopted | `apiKey` | Yes | Yes |
+
 | [Axolotl](https://theaxolotlapi.netlify.app/) | Collection of axolotl pictures and facts | No | Yes | No |
 | [Cat Facts](https://alexwohlbruck.github.io/cat-facts/) | Daily cat facts | No | Yes | No | |
 | [Cat Facts](https://catfact.ninja/) | Random cat facts | No | Yes | Yes |
-| [Cataas](https://cataas.com/) | Cat as a service (cats pictures and gifs) | No | Yes | No |
+
 | [Cats](https://docs.thecatapi.com/) | Pictures of cats from Tumblr | `apiKey` | Yes | No |
 | [Dog Facts](https://dukengn.github.io/Dog-facts-API/) | Random dog facts | No | Yes | Yes |
 | [Dog Facts](https://kinduff.github.io/dog-api/) | Random facts of Dogs | No | Yes | Yes |
@@ -140,10 +140,10 @@ API | Description | Auth | HTTPS | CORS
 | [FishWatch](https://www.fishwatch.gov/developers) | Information and pictures about individual fish species | No | Yes | Yes |
 | [HTTP Cat](https://http.cat/) | Cat for every HTTP Status | No | Yes | Yes |
 | [HTTP Dog](https://http.dog/) | Dogs for every HTTP response status code | No | Yes | Yes |
-| [IUCN](http://apiv3.iucnredlist.org/api/v3/docs) | IUCN Red List of Threatened Species | `apiKey` | No | No |
+| [IUCN](https://www.iucnredlist.org/en) | IUCN Red List of Threatened Species | `apiKey` | Yes | No |
 | [MeowFacts](https://github.com/wh-iterabb-it/meowfacts) | Get random cat facts | No | Yes | No |
 | [Movebank](https://github.com/movebank/movebank-api-doc) | Movement and Migration data of animals | No | Yes | Yes |
-| [Petfinder](https://www.petfinder.com/developers/) | Petfinder is dedicated to helping pets find homes, another resource to get pets adopted | `apiKey` | Yes | Yes |
+
 | [PlaceBear](https://placebear.com/) | Placeholder bear pictures | No | Yes | Yes |
 | [PlaceDog](https://place.dog) | Placeholder Dog pictures | No | Yes | Yes |
 | [RandomDog](https://random.dog/woof.json) | Random pictures of dogs | No | Yes | Yes |