add changelog

changelog/unreleased/fix-plugins-go1.21.md

@@ -0,0 +1,7 @@
+Bugfix: Fix plugin's registration when reva is build with version 1.21
+
+With go 1.21 the logic for package initialization has changed,
+and the plugins were failing in the registration.
+Now the registration of the plugins is deferred in the main.
+
+https://github.com/cs3org/reva/pull/4113