all: release v0.29.0 (#569)

CHANGES.md

diff --git a/CHANGES.md b/CHANGES.md
index 8a15d1b..5334afd 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,13 @@
+# v0.29.0
+
+## Changes
+
+- Various updates to autogenerated clients.
+- transport: internal bug fixes for mTLS.
+
+_Please note:_ the release version is not indicative of an individual client's
+stability or version.
+
 # v0.28.0
 
 ## Changes