Drop zchunk dependency

This is manually copying
7e915bf923

(Because we can't easily sync the spec file, because `%changelog`
 and all that stuff)

Resolves: rhbz#2028167

rpm-ostree.spec

@@ -4,7 +4,7 @@
 Summary: Hybrid image/package system
 Name: rpm-ostree
 Version: 2021.14
-Release: 2%{?dist}
+Release: 3%{?dist}
 License: LGPLv2+
 URL: https://github.com/coreos/rpm-ostree
 # This tarball is generated via "cd packaging && make -f Makefile.dist-packaging dist-snapshot"
@@ -25,10 +25,9 @@ BuildRequires: rust
 # Enable ASAN + UBSAN
 %bcond_with sanitizers
 
-# RHEL8 doesn't ship zchunk today.  See also the comments
-# in configure.ac around this as libdnf/librepo need to be in
-# sync, and today we bundle libdnf but not librepo.
-%if 0%{?rhel} && 0%{?rhel} <= 8
+# RHEL (8,9) doesn't ship zchunk today.  Keep this in sync
+# with libdnf: https://gitlab.com/redhat/centos-stream/rpms/libdnf/-/blob/762f631e36d1e42c63a794882269d26c156b68c1/libdnf.spec#L45
+%if 0%{?rhel}
 %bcond_with zchunk
 %else
 %bcond_without zchunk
@@ -213,6 +212,10 @@ $PYTHON autofiles.py > files.devel \
 %files devel -f files.devel
 
 %changelog
+* Wed Dec 01 2021 Colin Walters <walters@verbum.org> - 2021.14-3
+- Drop zchunk dependency
+  Resolves: rhbz#2028167
+
 * Mon Nov 29 2021 Colin Walters <walters@verbum.org> - 2021.14-2
 - https://github.com/coreos/rpm-ostree/releases/tag/v2021.14
   Resolves: rhbz#2027476