message: Fix unnecessary string clone in `Event:attr`
diff: @@ -143,7 +143,10 @@ impl Event {
  /// Add an attribute to the event.
  pub fn attr(mut self, key: impl Into<String>, value: impl Into<String>) -> Self {
  - self.attributes.push(crate::attr(key.into(), value.into()));
  + self.attributes.push(Attribute {
  + key: key.into(),
  + value: value.into(),
  + });
  self
  }
  }
  