Fixed comment about pathlib.link_to: it was added in 3.8, not changed. (#21851)

diff --git a/Doc/library/pathlib.rst b/Doc/library/pathlib.rst
index f705d15..04810f5 100644
--- a/Doc/library/pathlib.rst
+++ b/Doc/library/pathlib.rst
@@ -1134,7 +1134,7 @@
 
    Create a hard link pointing to a path named *target*.
 
-   .. versionchanged:: 3.8
+   .. versionadded:: 3.8
 
 
 .. method:: Path.write_bytes(data)