CHANGELOG: bump 0.29.0 minimum tailscale client to v1.80.0

Reflects the capver floor move from 109 (v1.78) to 113 (v1.80) that
ships with this release.

Author: kradalby

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 0.29.0 (202x-xx-xx)
 
-**Minimum supported Tailscale client version: v1.76.0**
+**Minimum supported Tailscale client version: v1.80.0**
 
 ### Tailscale ACL compatibility improvements