pango: gir set manual impl for some functions

Functions `itemize()` & `itemize_with_base_dir` now use Into<Option<&_>> for the
`cached_dir` argument. Because of this new signature, the lifetime for the inner
type `AttrIterator<'_>>` must be specified.

Author: fengalin

pango/Gir.toml

@@ -95,14 +95,12 @@ status = "generate"
     ignore = true
     [[object.function]]
     name = "itemize"
-        [[object.function.parameter]]
-        name = "cached_iter"
-        const = true
+    # Needs explicite lifetime for AttrIterator
+    manual = true
     [[object.function]]
     name = "itemize_with_base_dir"
-        [[object.function.parameter]]
-        name = "cached_iter"
-        const = true
+    # Needs explicite lifetime for AttrIterator
+    manual = true
     [[object.function]]
     name = "reorder_items"
     manual = true