Remove unused type Jsx.ref (#7459)

* Remove unused type Jsx.ref

* CHANGELOG

Author: cknitt

CHANGELOG.md

@@ -43,6 +43,7 @@
 
 - In type errors, recommend stdlib over Belt functions for converting between float/int/string. https://github.com/rescript-lang/rescript/pull/7453
 - Make `Jsx.element` a private empty record to avoid unnecessary `Primitive_option.some`. https://github.com/rescript-lang/rescript/pull/7450
+- Remove unused type `Jsx.ref`. https://github.com/rescript-lang/rescript/pull/7459
 
 # 12.0.0-alpha.12
 

runtime/Jsx.res

@@ -26,8 +26,6 @@
 // unnecessarily add `Primitive_option.some` calls for optional props.
 type element = private {}
 
-type ref
-
 @val external null: element = "null"
 
 external float: float => element = "%identity"