forgejo-hooks: merged_at attribute is optional

Signed-off-by: pep <pep@bouah.net>

forgejo-hooks/src/lib.rs

@@ -233,7 +233,7 @@ pub enum IssueState {
 #[derive(Deserialize, Debug, PartialEq)]
 pub struct PullRequestMeta {
 	pub merged: bool,
-	pub merged_at: DateTime<Utc>,
+	pub merged_at: Option<DateTime<Utc>>,
 	pub draft: bool,
 	pub html_url: String,
 }