Fix write on render warning with read only signal props (#3194)

packages/signals/src/read_only_signal.rs

@@ -52,7 +52,12 @@ impl<T: 'static, S: Storage<SignalData<T>>> ReadOnlySignal<T, S> {
     /// Mark any readers of the signal as dirty
     pub fn mark_dirty(&mut self) {
         use crate::write::Writable;
-        _ = self.inner.try_write();
+        use warnings::Warning;
+        // We diff props while rendering, but we only write to the signal if it has
+        // changed so it is safe to ignore the warning
+        crate::warnings::signal_write_in_component_body::allow(|| {
+            _ = self.inner.try_write();
+        });
     }
 }