Update CHANGELOGs for release (#1059)

protobuf/CHANGELOG.md

diff --git a/protobuf/CHANGELOG.md b/protobuf/CHANGELOG.md
index 2412b28..2874f12 100644
--- a/protobuf/CHANGELOG.md
+++ b/protobuf/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 5.0.0-wip
+## 5.0.0
 
 * Improve performance of `GeneratedMessage.deepCopy`. ([#742])
 * Fix unknown enum handling in `GeneratedMessage.mergeFromProto3Json` when

protoc_plugin/CHANGELOG.md

diff --git a/protoc_plugin/CHANGELOG.md b/protoc_plugin/CHANGELOG.md
index 9dd8914..78c9754 100644
--- a/protoc_plugin/CHANGELOG.md
+++ b/protoc_plugin/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 23.0.0-wip
+## 23.0.0
 
 Note: this version requires protobuf 5.0.0.