Testing showed that while race condition analysis in #3880 was correct, the way it tries to fix that
does not work for the *first* git-lfs process that will actually perform file move.
Instead, this commit performs multiple attempts when working with files in LFS storage.
Similar logic is already implemented in "cmd/go/internal/robustio" and "cmd/go/internal/renameio" packages.
However, they are not public, so we cannot use them.
