Remove "public" mention of primitivevalidator package

Author: Ivan De Marino

.changelog/42.txt

@@ -13,7 +13,3 @@ numbervalidator: New package that starts with 2 validation functions, `OneOf()`
 ```release-note:enhancement
 stringvalidator: 2 new validation functions, `OneOf()` and `NoneOf()`, similar to the ones in `genericvalidator` but option to control case-sensitivity
 ```
-
-```release-note:note
-Introduced a new package `primitivevalidator`, holding the shared code used by type-specific validators (ex. `OneOf()` and `NoneOf()`)
-```