Remove deprecated authenticationSessionId from embedder API cont

src/vs/workbench/workbench.web.api.ts

@@ -264,13 +264,6 @@ interface IWorkbenchConstructionOptions {
 	 */
 	readonly connectionToken?: string;
 
-	/**
-	 * Session id of the current authenticated user
-	 *
-	 * @deprecated Instead pass current authenticated user info through [credentialsProvider](#credentialsProvider)
-	 */
-	readonly authenticationSessionId?: string;
-
 	/**
 	 * An endpoint to serve iframe content ("webview") from. This is required
 	 * to provide full security isolation from the workbench host.