sync: revert
423ab2f61b410c3e46451b01913f9cd6b4f2d82c
Using the chroot path for `repo-filter --sysroot` has two limitations:
* If the chroot was not created (`aur chroot --create` or `aur build
--chroot`) before `aur-sync` is run, an error message appears;
* `repo-filter --sysroot` is run before `aur-build`, specifically before new
pacman databases are pulled to the container with `pacman -Syu`.
This is an inherent limitation with seperating fetch/repo-filter from aur-build
in aur-sync. The chroot create/upgrade step could however be moved to `aur-sync`
in a later commit, with `aur-build` optionally not running this step by default.