install: support reflink

[oech3]

Fixes #13058

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/rm/many-dir-entries-vs-OOM is now being skipped but was previously passing.
Congrats! The gnu test tests/printf/printf-surprise is now passing!

[oech3]

@sylvestre Would you review this?

[oech3]

Is this worth to catch

> strace -qqq -e trace=ioctl target/debug/install /etc/pacman.conf /tmp/a
ioctl(4, BTRFS_IOC_CLONE or FICLONE, 3) = -1 EXDEV (Invalid cross-device link)

on the test even mount does not work on the CI?