Mark internal_tracker as optional.

src/hook_push.rs

@@ -89,6 +89,8 @@ pub(crate) struct HookRepository {
     archived_at: String, // TODO: parse to datetime
     permissions: HookRepositoryPermissions,
     has_issues: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    internal_tracker: Option<HookRepositoryInternalTracker>,
     has_wiki: bool,
     has_pull_requests: bool,
     has_projects: bool,
@@ -125,6 +127,15 @@ pub(crate) struct HookRepositoryPermissions {
     pull: bool,
 }
 
+#[allow(dead_code)]
+#[derive(Debug, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub(crate) struct HookRepositoryInternalTracker {
+    enable_time_tracker: bool,
+    allow_only_contributors_to_track_time: bool,
+    enable_issue_dependencies: bool,
+}
+
 #[allow(dead_code)]
 #[derive(Debug, Deserialize)]
 #[serde(deny_unknown_fields)]