Allow unused_braces for ignore nightly doc builds

Regression
rust-lang/rust#70814

Author: martell

diesel_derives/src/lib.rs

@@ -18,7 +18,11 @@
     clippy::items_after_statements,
     clippy::used_underscore_binding
 )]
-#![cfg_attr(feature = "nightly", feature(proc_macro_diagnostic, proc_macro_span))]
+// Nightly Regression https://github.com/rust-lang/rust/issues/70814
+#![cfg_attr(
+    feature = "nightly",
+    feature(proc_macro_diagnostic, proc_macro_span, unused_braces)
+)]
 
 extern crate proc_macro;
 extern crate proc_macro2;

diesel_migrations/migrations_macros/src/lib.rs

@@ -20,6 +20,8 @@
     clippy::items_after_statements,
     clippy::used_underscore_binding
 )]
+// Nightly Regression https://github.com/rust-lang/rust/issues/70814
+#![cfg_attr(feature = "nightly", feature(unused_braces))]
 #![cfg_attr(test, allow(clippy::option_unwrap_used, clippy::result_unwrap_used))]
 extern crate migrations_internals;
 extern crate proc_macro;