Removed support for writting IMAER version 5.1. It's not used anymore. (#378)

Author: Hilbrand

source/imaer-gml/src/main/java/nl/overheid/aerius/gml/base/GMLVersionWriterFactory.java

@@ -18,7 +18,6 @@
 
 import javax.xml.validation.Schema;
 
-import nl.overheid.aerius.gml.v5_1.togml.GMLVersionWriterV51;
 import nl.overheid.aerius.gml.v6_0.togml.GMLVersionWriterV60;
 import nl.overheid.aerius.shared.domain.geo.HexagonZoomLevel;
 import nl.overheid.aerius.shared.exception.AeriusException;
@@ -32,7 +31,6 @@ private GMLVersionWriterFactory() {
   public static GMLVersionWriter createGMLVersionWriter(final HexagonZoomLevel zoomLevel1, final String srsName,
       final AeriusGMLVersion aeriusGMLVersion, final boolean withRepresentation) {
     return switch (aeriusGMLVersion) {
-      case V5_1 -> new GMLVersionWriterV51(zoomLevel1, srsName);
       case V6_0 -> new GMLVersionWriterV60(zoomLevel1, srsName, withRepresentation);
       default -> throw new IllegalArgumentException("Aerius GML version is not supported");
     };