Fixes a Mypy issue and prefers comment over exception (ignored) message

Author: Samuel FORESTIER

src/distro/distro.py

@@ -1105,6 +1105,7 @@ def __resolve_chroot_symlink_as_needed(self, link_location: str) -> str:
         return self.__resolve_chroot_symlink(link_location)
 
     def __resolve_chroot_symlink(self, link_location: str) -> str:
+        assert self.root_dir is not None
         if os.path.commonprefix([self.root_dir, link_location]) != self.root_dir:
             raise FileNotFoundError
 
@@ -1122,9 +1123,8 @@ def __resolve_chroot_symlink(self, link_location: str) -> str:
                     )
                     != os.path.realpath(self.root_dir)
                 ):
-                    raise FileNotFoundError(
-                        f"{link_location} resolves outside of {self.root_dir}."
-                    ) from None
+                    # `link_location` resolves outside of `self.root_dir`.
+                    raise FileNotFoundError from None
 
                 return link_location