fix: Do not fail to open file with relative paths

resolve()	absolute()
Make the path absolute, resolving any symlinks. A new path object is returned	Make the path absolute, without normalization or resolving symlinks

Please see: https://docs.python.org/3/library/pathlib.html#pathlib.Path.resolve

I went for resolve. Any reason, why absolute would be better in our cases instead?

Fixes #12490 (closed)