[doc] Update release notes (#4509)

Closes #4509

docs/pages/release_notes.md

@@ -378,6 +378,7 @@ Language specific fixes:
     * [#4427](https://github.com/pmd/pmd/issues/4427): \[apex] ApexBadCrypto test failing to detect inline code
 * apex-design
     * [#2667](https://github.com/pmd/pmd/issues/2667): \[apex] Integrate nawforce/ApexLink to build robust Unused rule
+    * [#4509](https://github.com/pmd/pmd/issues/4509): \[apex] ExcessivePublicCount doesn't consider inner classes correctly
 * java
     * [#520](https://github.com/pmd/pmd/issues/520):   \[java] Allow `@SuppressWarnings` with constants instead of literals
     * [#864](https://github.com/pmd/pmd/issues/864):   \[java] Similar/duplicated implementations for determining FQCN

pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/design/xml/ExcessivePublicCount.xml

@@ -115,7 +115,7 @@ public class SomeClass {
     </test-code>
 
     <test-code>
-        <description>class with inner classes</description>
+        <description>#4509 class with inner classes</description>
         <rule-property name="minimum">1</rule-property>
         <expected-problems>2</expected-problems>
         <expected-linenumbers>1,5</expected-linenumbers>