configs/releng/profiledef.sh: use zstd compression for bootstrap image

The zstd tool has now been around for a while, so the availability of
it should not be a concern anymore.

Unlike gzip which was used until now, zstd offers higher compression
while still being faster (and multi-threaded).
The `--auto-threads=logical` option is used just so that there is some
difference between the releng and baseline profiles.

Everyone using the official Arch Linux bootstrap tarball (previously
`archlinux-bootstrap-YYYY.MM.DD-x86_64.tar.gz` or
`archlinux-bootstrap-x86_64.tar.gz`) will need to update their scripts
and etc. to use `archlinux-bootstrap-YYYY.MM.DD-x86_64.tar.zst` or
`archlinux-bootstrap-x86_64.tar.zst` instead.

Implements https://gitlab.archlinux.org/archlinux/archiso/-/issues/130

1 files changed, 2 insertions, 0 deletions

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 388cba3..0592b94 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -14,6 +14,8 @@ Added
 Changed
 -------
 
+- Change releng profile's bootstrap tarball compression from gzip to zstd. zstd provides higher and faster compression.
+
 Deprecated
 ----------