Remove unused versions

Author: thecoop

server/src/main/java/org/elasticsearch/TransportVersions.java

@@ -55,8 +55,6 @@ static TransportVersion def(int id) {
     public static final TransportVersion V_7_0_1 = def(7_00_01_99);
     public static final TransportVersion V_7_2_0 = def(7_02_00_99);
     public static final TransportVersion V_7_2_1 = def(7_02_01_99);
-    public static final TransportVersion V_7_3_0 = def(7_03_00_99);
-    public static final TransportVersion V_7_4_0 = def(7_04_00_99);
     public static final TransportVersion V_7_5_0 = def(7_05_00_99);
     public static final TransportVersion V_7_6_0 = def(7_06_00_99);
     public static final TransportVersion V_7_7_0 = def(7_07_00_99);