refactor(examples): Use if-let chains in oauth_cli

Author: jplatte

examples/oauth_cli/src/main.rs

@@ -140,12 +140,10 @@ impl OAuthCli {
         let cli = Self { client, restored: false, session_file };
 
         if let Err(error) = cli.register_and_login().await {
-            if error.downcast_ref::<OAuthError>().is_some_and(|error| {
-                matches!(
-                    error,
-                    OAuthError::ClientRegistration(OAuthClientRegistrationError::NotSupported)
-                )
-            }) {
+            if let Some(error) = error.downcast_ref::<OAuthError>()
+                && let OAuthError::ClientRegistration(OAuthClientRegistrationError::NotSupported) =
+                    error
+            {
                 // This would require to register with the authorization server manually, which
                 // we don't support here.
                 bail!(