fix(rust): Fix code snippet (#15423)

Author: lcian

docs/platforms/rust/guides/tracing/index.mdx

@@ -58,7 +58,7 @@ fn main() {
             # ___PRODUCT_OPTION_END___ logs
             ..sentry::ClientOptions::default()
         },
-    });
+    ));
 
     // Register the Sentry tracing layer
     tracing_subscriber::registry()