[doc] Update release notes (#4280)

docs/pages/release_notes.md

@@ -18,7 +18,17 @@ This is a {{ site.pmd.release_type }} release.
 
 ### API Changes
 
+#### Deprecated APIs
+
+##### For removal
+
+* {% jdoc !!apex::lang.apex.ast.ApexRootNode#getApexVersion() %} has been deprecated for removal. The version returned is
+  always `Version.CURRENT`, as the apex compiler integration doesn't use additional information which Apex version
+  actually is used. Therefore, this method can't be used to determine the Apex version of the project
+  that is being analyzed.
+
 ### External Contributions
+* [#4280](https://github.com/pmd/pmd/pull/4280): \[apex] Deprecate ApexRootNode.getApexVersion - [Aaron Hurst](https://github.com/aaronhurst-google) (@aaronhurst-google)
 
 {% endtocmaker %}
 

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/ast/ApexRootNode.java

@@ -46,6 +46,9 @@ public abstract class ApexRootNode<T extends Compilation> extends AbstractApexNo
      * Use {@link Version} to compare, e.g.
      * {@code node.getApexVersion() >= Version.V176.getExternal()}
      * @return the apex version
+     * @deprecated for removal. The version returned is always Version.CURRENT, as the apex compiler integration
+     *      doesn't use additional information which Apex version actually is used. Therefore, this method can't be
+     *      used to determine the Apex version of the project that is being analyzed.
      */
     @Deprecated
     public double getApexVersion() {