chore(javac): update javac args to allow errorprone on JDK21

Author: nielm

pom.xml

@@ -144,6 +144,8 @@
             <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED</arg>
             <arg>-J--add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED</arg>
             <arg>-J--add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED</arg>
+            <!-- Required for errorprone in JDK21 See https://errorprone.info/docs/installation -->
+            <arg>-XDaddTypeAnnotationsToSymbol=true</arg>
           </compilerArgs>
           <annotationProcessorPaths>
             <path>