Migrate item_opaque_type to Askama

Migrate item_opaque_type to Askama

Fix wrap_item parameters

Fix to write

src/librustdoc/html/render/print_item.rs

@@ -1124,7 +1124,12 @@ fn item_trait_alias(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &
     write!(w, "{}", render_assoc_items(cx, it, it.item_id.expect_def_id(), AssocItemRender::All))
 }
 
-fn item_opaque_ty(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::OpaqueTy) {
+fn item_opaque_ty(
+    w: &mut impl fmt::Write,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    t: &clean::OpaqueTy,
+) {
     wrap_item(w, |w| {
         write!(
             w,
@@ -1134,16 +1139,18 @@ fn item_opaque_ty(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &cl
             where_clause = print_where_clause(&t.generics, cx, 0, Ending::Newline),
             bounds = bounds(&t.bounds, false, cx),
             attrs = render_attributes_in_pre(it, "", cx.tcx()),
-        );
+        )
+        .unwrap();
     });
 
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2)).unwrap();
 
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
     // associated items from the aliased type (see discussion in #32077), but
     // we need #14072 to make sense of the generics.
     write!(w, "{}", render_assoc_items(cx, it, it.item_id.expect_def_id(), AssocItemRender::All))
+        .unwrap();
 }
 
 fn item_typedef(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::Typedef) {