Add OnTicketReceived event to OIDC documentation

Documented the `OnTicketReceived` event in OpenID Connect handler. Includes details on its purpose, trigger points, use cases for authentication ticket customization, and related diagnostics.

Author: khalidabuhakmeh

src/content/docs/identityserver/fundamentals/openid-connect-events.md

@@ -77,6 +77,7 @@ identity provider. Understanding the direction of these events can help you dete
 | `OnTokenResponseReceived`                | **Incoming** |
 | `OnTokenValidated`                       | **Incoming** |
 | `OnUserInformationReceived`              | **Incoming** |
+| `OnTicketReceived`                       | **Incoming** |
 | `OnPushAuthorization` (**.NET 9+ only**) | **Outgoing** |
 
 ## Commonly Subscribed Events
@@ -174,6 +175,15 @@ For ASP.NET Core developers, the most commonly subscribed events are:
   endpoint.
 - **Commonly subscribed**: Sometimes, if extra claims processing is required.
 
+### OnTicketReceived
+
+- **When called**: Invoked after the OpenID Connect authentication flow is complete and before the authentication ticket
+  is returned.
+- **How often**: Called once per successful authentication flow completion.
+- **Example use case**: Modify the final authentication ticket, perform additional validation, or execute custom logic
+  before completing the authentication process.
+- **Commonly subscribed**: Sometimes, when final authentication customization is needed before completing the flow or for diagnostics and troubleshooting purposes.
+
 ### OnPushAuthorization
 
 - **When called**: Invoked before sending authorization parameters using the Pushed Authorization Request (PAR)