Fix #114: Move productname close to productid (#115)

* Make them closer to better find it
* Correct return type to include None

Author: tomschr

src/docbuild/models/deliverable.py

@@ -29,10 +29,16 @@ class Deliverable:
     _meta: Metadata | None = None
 
     @cached_property
-    def productid(self) -> str:
+    def productid(self) -> str|None:
         """Return the product ID."""
         # ancestor::product/@productid
-        return next(self._node.iterancestors('product')).attrib.get('productid')
+        return self.product_node.attrib.get('productid', None)
+
+    @cached_property
+    def productname(self) -> str|None:
+        """Return the product name."""
+        # ancestor::product/name
+        return self.product_node.findtext('name', default=None, namespaces=None)
 
     @cached_property
     def docsetid(self) -> str:
@@ -185,12 +191,6 @@ def node(self) -> etree._Element:
         """Return the node of the deliverable."""
         return self._node
 
-    @cached_property
-    def productname(self) -> str:
-        """Return the product name or None if not found."""
-        # anecstor::product/name
-        return self.product_node.findtext('name', default=None, namespaces=None)
-
     @cached_property
     def acronym(self) -> str:
         """Return the product acronym or None if not found."""