Mention that we dropped id from free objects in the changelog (#8392

)

Co-authored-by: Scott Trinh <[email protected]>

docs/resources/changelog/6_x.rst

@@ -305,6 +305,18 @@ Additional changes
 EdgeQL
 ------
 
+* Free objects no longer have an ``id`` property. This is a breaking
+  change, though we expect the real-world impact to be minor. If you
+  need a dynamically generated new ID for free objects, it can be
+  added manually, using one of our UUID generation functions.
+
+  .. code-block:: edgeql
+
+    select {
+        id := uuid_generate_v1mc(),
+        property := 'Some string',
+    }
+
 * Add ``__default__`` keyword to refer to default value.
   (:eql:gh:`#7214`)