Add CHANGELOG entry

Author: mediremi

CHANGELOG.md

@@ -28,6 +28,7 @@
 - Fix parse error with nested record types and attributes on the field name that has the nested record type. https://github.com/rescript-lang/rescript/pull/7781
 - Fix ppx resolution with package inside monorepo. https://github.com/rescript-lang/rescript/pull/7776
 - Fix 'Unbound module type' errors that occurred when trying to async import modules. https://github.com/rescript-lang/rescript/pull/7783
+- Fix creating interface for functions with upper bounded polymorphic args. https://github.com/rescript-lang/rescript/pull/7786
 
 #### :memo: Documentation