[3.12] gh-105002: [pathlib] Fix relative_to with walk_up=True using ".." (GH-107014) (#107315)

gh-105002: [pathlib] Fix relative_to with walk_up=True using ".." (GH-107014)

It makes sense to raise an Error because ".." can not
be resolved and the current working directory is unknown.
(cherry picked from commit e7e6e4b035f51ab4a962b45a957254859f264f4f)

Co-authored-by: János Kukovecz <kukoveczjanos@gmail.com>