Remove unused field

Fixes spotbugs

Author: soerenreichardt

io/core/src/main/java/org/neo4j/gds/core/io/file/NodeVisitor.java

@@ -111,7 +111,6 @@ void reset() {
 
     abstract static class Builder<SELF extends Builder<SELF, VISITOR>, VISITOR extends NodeVisitor> {
         NodeSchema nodeSchema;
-        boolean reverseIdMap;
 
         SELF withNodeSchema(NodeSchema nodeSchema) {
             this.nodeSchema = nodeSchema;