Fix extra quote in JavaDoc link for EventHubClientBuilder

Removed the extra quotation mark inside the anchor tag for the Azure
Identity documentation link. This malformed HTML was causing the
"Extra label found: <xref" content validation error.

Fixes #47386

Co-authored-by: samvaity <[email protected]>

Author: Copilot

sdk/eventhubs/azure-messaging-eventhubs/src/main/java/com/azure/messaging/eventhubs/EventHubClientBuilder.java

@@ -99,7 +99,7 @@
  * <a href="https://learn.microsoft.com/azure/active-directory/managed-identities-azure-resources/">managed identity</a>
  * for authentication in production environments.  You can find more information on different ways of authenticating and
  * their corresponding credential types in the
- * <a href="https://learn.microsoft.com/java/api/overview/azure/identity-readme">Azure Identity documentation"</a>.
+ * <a href="https://learn.microsoft.com/java/api/overview/azure/identity-readme">Azure Identity documentation</a>.
  * </p>
  *
  * <p><strong>Sample: Construct a {@link EventHubProducerAsyncClient}</strong></p>