[cleanup] use self.origin attribute instead of property

There is no reason tjo have properties here instead of an attribute

Change-Id: I8ed6bed0dd7bc28a5855893b2b0c1d0d49f4712a
---
M pywikibot/interwiki_graph.py
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/pywikibot/interwiki_graph.py b/pywikibot/interwiki_graph.py
index 66eb8be..40d67c4 100644
--- a/pywikibot/interwiki_graph.py
+++ b/pywikibot/interwiki_graph.py
@@ -62,7 +62,7 @@
         :param origin: the page on the 'origin' wiki
         """
         # Remember the "origin page"
-        self._origin = origin
+        self.origin = origin
 
         # found_in is a dictionary where pages are keys and lists of
         # pages are values. It stores where we found each page.
@@ -72,15 +72,6 @@
         if origin:
             self.found_in = {origin: []}
 
-    @property
-    def origin(self) -> pywikibot.page.Page | None:
-        """Page on the origin wiki."""
-        return self._origin
-
-    @origin.setter
-    def origin(self, value: pywikibot.page.Page | None) -> None:
-        self._origin = value
-
 
 class GraphDrawer:
 

