core: add version 4.3.1 in ChangeLog and upgrade guidelines

CHANGELOG.md

@@ -20,6 +20,21 @@
 - tests: fix compilation of tests on Fedora 40 ([#2116](https://github.com/weechat/weechat/issues/2116))
 - tests: fix compilation of tests on Rocky 9.4
 
+## Version 4.3.1 (2024-05-31)
+
+### Fixed
+
+- irc: close /list buffer when the server buffer is closed ([#2121](https://github.com/weechat/weechat/issues/2121))
+- xfer: fix send of data on the DCC chat buffer after `/upgrade` if the buffer was opened before the upgrade ([#2092](https://github.com/weechat/weechat/issues/2092))
+- php: fix return value of function hdata_longlong
+- tcl: fix return value of function hdata_longlong ([#2119](https://github.com/weechat/weechat/issues/2119))
+- core: fix detection of libgcrypt ≥ 1.11 ([debian #1071960](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1071960))
+- core, relay: fix include directory of libcjson and libzstd
+- tests: fix relay tests on s390x ([#2118](https://github.com/weechat/weechat/issues/2118))
+- tests: fix check of php plugin ([#2117](https://github.com/weechat/weechat/issues/2117))
+- tests: fix compilation of tests on Fedora 40 ([#2116](https://github.com/weechat/weechat/issues/2116))
+- tests: fix compilation of tests on Rocky 9.4
+
 ## Version 4.3.0 (2024-05-26)
 
 _If you are upgrading: please see [UPGRADING.md](UPGRADING.md)._

UPGRADING.md

@@ -7,6 +7,15 @@ When upgrading from version X to Y, please read and apply all instructions from
 
 For a list of all changes in each version, please see [CHANGELOG.md](CHANGELOG.md).
 
+## Version 4.3.1
+
+### Detection of libgcrypt
+
+The detection of libgcrypt has been fixed to properly detect libgcrypt ≥ 1.11.\
+As a consequence, the detection of an old version of libgcrypt is failing if the
+file `libgcrypt.pc` is not found.\
+This affects old distributions like Debian Buster and Ubuntu Bionic.
+
 ## Version 4.3.0
 
 ### Relay options