Add release marker for build-id 7129

Author: syssimics

RELEASENOTES-1.4.md

@@ -406,4 +406,5 @@
 - `note 6` The method implementations that may be incurred by instantiating the
   `read_field`, `write_field`, `read`, or `write` templates have all been made
   overridable. See the documentation of these templates for more details.
+- `release 7 7129`
 - `release 6 6444`