Symlink pg_replslot robustly on Windows in pg_basebackup test
This reverts commit
e9f15bc9. Instead of a hacky solution that didn't
work on Windows, we avoid trying to move the directory possibly across
drives, and instead remove it and recreate it in the new location.
Discussion: https://postgr.es/m/
20240707070243.sb77kp4ubowauctz@awork3.anarazel.de
Backpatch to release 14 like the previous patch.