Merge version 1.21.17+rpi1 and 1.21.18 to produce 1.21.18+rpi1

diff --cc debian/changelog
index 830b0adc52f37220927d07f78fd091194a739740,d158f167e3cf7981969c4e685064566081c3af03..ccb34542f0dc5fcd2b2227a7a5f7851485df0a3b
--- 1/debian/changelog
--- 2/debian/changelog
+++ b/debian/changelog
@@@ -1,13 -1,27 +1,38 @@@
- dpkg (1.21.17+rpi1) bookworm-staging; urgency=medium
++dpkg (1.21.18+rpi1) bookworm-staging; urgency=medium
 +
 +  [changes brought forward from 1.20.5+rpi1 by Peter Michael Green <plugwash@raspbian.org> at Sun, 02 Aug 2020 12:08:02 +0000]
 +  * Hack up Vendor.pm so it doesn't fail
 +    (see https://lists.debian.org/debian-dpkg/2020/08/msg00004.html )
 +
 +  [changes introduce in 1.21.17+rpi1 by Peter Michael Green]
 +  * disable testsuite.
 +
-  -- Peter Michael Green <plugwash@raspbian.org>  Sun, 15 Jan 2023 18:39:18 +0000
++ -- Raspbian forward porter <root@raspbian.org>  Tue, 17 Jan 2023 09:57:25 +0000
++
+ dpkg (1.21.18) unstable; urgency=medium
+ 
+   [ Guillem Jover ]
+   * Perl modules:
+     - Dpkg::BuildFlags: Fix strip method to always work with duplicates.
+       Closes: #1028044
+   * Documentation:
+     - man: Add a note to dpkg-fsys-usrunmess(8) about Debian support.
+       Closes: #1008486
+   * Code internals:
+     - libdpkg: Move compression level max bound check from dpkg-deb.
+     - libdpkg: Switch dpkg_lzma_strerror() to use struct io_lzma.
+     - libdpkg: Split compression filter operation tracking from its status.
+     - libdpkg: Generalize compression stream action handling.
+     - libdpkg: Abstract compression stream status tracking.
+     - libdpkg: Add zstd support for .deb archives. Closes: #892664
+   * Build system:
+     - Update .mailmap mappings.
+   * Packaging:
+     - Update copyright years.
+   * Test suite:
+     - Add dpkg-deb build and extract tests.
+ 
+  -- Guillem Jover <guillem@debian.org>  Tue, 10 Jan 2023 18:46:37 +0100
  
  dpkg (1.21.17) unstable; urgency=medium
  

diff --cc debian/rules
Simple merge