Add version constant for 7.6.1

Author: polyfractal

.ci/bwcVersions

@@ -52,5 +52,5 @@ BWC_VERSION:
   - "7.5.0"
   - "7.5.1"
   - "7.5.2"
-  - "7.5.3"
   - "7.6.0"
+  - "7.6.1"

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

@@ -127,8 +127,8 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_7_5_0 = new Version(7050099, org.apache.lucene.util.Version.LUCENE_8_3_0);
     public static final Version V_7_5_1 = new Version(7050199, org.apache.lucene.util.Version.LUCENE_8_3_0);
     public static final Version V_7_5_2 = new Version(7050299, org.apache.lucene.util.Version.LUCENE_8_3_0);
-    public static final Version V_7_5_3 = new Version(7050399, org.apache.lucene.util.Version.LUCENE_8_3_0);
     public static final Version V_7_6_0 = new Version(7060099, org.apache.lucene.util.Version.LUCENE_8_4_0);
+    public static final Version V_7_6_1 = new Version(7060199, org.apache.lucene.util.Version.LUCENE_8_4_0);
     public static final Version V_7_7_0 = new Version(7070099, org.apache.lucene.util.Version.LUCENE_8_5_0);
     public static final Version CURRENT = V_7_7_0;