doc: fix Code.path: might return str

src/_pytest/_code/code.py

@@ -68,8 +68,9 @@ class Code:
 
     @property
     def path(self) -> Union[py.path.local, str]:
-        """ return a path object pointing to source code (note that it
-        might not point to an actually existing file). """
+        """ return a path object pointing to source code (or a str in case
+        of OSError / non-existing file).
+        """
         try:
             p = py.path.local(self.raw.co_filename)
             # maybe don't try this checking