[bugfix] Use version 4.9.3 of Antlr which is the last version with Java 8 compatibility

Author: adamretter

pom.xml

@@ -41,7 +41,8 @@
         <project.build.source>1.8</project.build.source>
         <project.build.target>1.8</project.build.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <antlr.version>4.13.1</antlr.version>
+        <!-- NOTE(AR) Antlr 4.9.3 is the last version in the 4.x.x line that supports Java 8 -->
+        <antlr.version>4.9.3</antlr.version>
         <contact.email>[email protected]</contact.email>
     </properties>