CI: autofix rust code.

src/parser/comment.rs

@@ -52,7 +52,7 @@ pub fn comment<'r, 's>(
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 fn comment_line<'r, 's>(
-    context: Context<'r, 's>,
+    _context: Context<'r, 's>,
     input: OrgSource<'s>,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     start_of_line(input)?;