docs(event_handler): fix typo in api keys swagger url (#6536)

Signed-off-by: victorperezpiqueras <[email protected]>

Author: victorperezpiqueras

docs/core/event_handler/api_gateway.md

@@ -1146,7 +1146,7 @@ OpenAPI 3 lets you describe APIs protected using the following security schemes:
 | Security Scheme                                                                                                                                                                         | Type            | Description                                                                                                                                                                                                                                                                         |
 | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | [HTTP auth](https://www.iana.org/assignments/http-authschemes/http-authschemes.xhtml){target="_blank"}                                                                                  | `HTTPBase`      | HTTP authentication schemes using the Authorization header (e.g: [Basic auth](https://swagger.io/docs/specification/authentication/basic-authentication/){target="_blank"}, [Bearer](https://swagger.io/docs/specification/authentication/bearer-authentication/){target="_blank"}) |
-| [API keys](https://swagger.io/docs/specification/authentication/api-keys/https://swagger.io/docs/specification/authentication/api-keys/){target="_blank"} (e.g: query strings, cookies) | `APIKey`        | API keys in headers, query strings or [cookies](https://swagger.io/docs/specification/authentication/cookie-authentication/){target="_blank"}.                                                                                                                                      |
+| [API keys](https://swagger.io/docs/specification/authentication/api-keys/){target="_blank"} (e.g: query strings, cookies) | `APIKey`        | API keys in headers, query strings or [cookies](https://swagger.io/docs/specification/authentication/cookie-authentication/){target="_blank"}.                                                                                                                                      |
 | [OAuth 2](https://swagger.io/docs/specification/authentication/oauth2/){target="_blank"}                                                                                                | `OAuth2`        | Authorization protocol that gives an API client limited access to user data on a web server.                                                                                                                                                                                        |
 | [OpenID Connect Discovery](https://swagger.io/docs/specification/authentication/openid-connect-discovery/){target="_blank"}                                                             | `OpenIdConnect` | Identity layer built [on top of the OAuth 2.0 protocol](https://openid.net/developers/how-connect-works/){target="_blank"} and supported by some OAuth 2.0.                                                                                                                         |
 | [Mutual TLS](https://swagger.io/specification/#security-scheme-object){target="_blank"}.                                                                                                | `MutualTLS`     | Client/server certificate mutual authentication scheme. |