[kotlin] Prevent auxiliary grammars from generating lexers (#5335)

Merge pull request #5335 from Monits:fix-generated-code-kotlin

docs/pages/release_notes.md

@@ -47,6 +47,9 @@ This is a {{ site.pmd.release_type }} release.
 * pmd-xml
   * {%jdoc xml::lang.xml.antlr4.XMLLexer %} is deprecated for removal. Use {%jdoc !!xml::lang.xml.ast.XMLLexer %}
     instead (note different package `ast` instead of `antlr4`).
+* pmd-kotlin
+  * {%jdoc kotlin::lang.kotlin.ast.UnicodeClasses %} is deprecated for removal. This class was never intended to
+    be generated. It will be removed with no replacement.
 
 ### ✨ External Contributions
 * [#5284](https://github.com/pmd/pmd/pull/5284): \[apex] Use case-insensitive input stream to avoid choking on Unicode escape sequences - [Willem A. Hajenius](https://github.com/wahajenius) (@wahajenius)