Update version to 2.18.0 for CatShards request and response (#16455)

* Update version to 2.18.0 for CatShards request and response

Signed-off-by: Harsh Garg <gkharsh@amazon.com>

* Retry Build

Signed-off-by: Harsh Garg <gkharsh@amazon.com>

* Fix CatShardsRequestTests

Signed-off-by: Harsh Garg <gkharsh@amazon.com>

* Retry Build

Signed-off-by: Harsh Garg <gkharsh@amazon.com>

---------

Signed-off-by: Harsh Garg <gkharsh@amazon.com>
Co-authored-by: Harsh Garg <gkharsh@amazon.com>
(cherry picked from commit 119abaf)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

server/src/test/java/org/opensearch/action/admin/cluster/shards/CatShardsRequestTests.java

@@ -95,7 +95,7 @@ public void testSerializationWithOlderVersionsParametersNotSerialized() throws E
         catShardsRequest.setCancelAfterTimeInterval(TimeValue.timeValueMillis(randomIntBetween(1, 5)));
         catShardsRequest.setIndices(new String[2]);
 
-        Version version = VersionUtils.getPreviousVersion(Version.CURRENT);
+        Version version = VersionUtils.getPreviousVersion(Version.V_2_18_0);
         try (BytesStreamOutput out = new BytesStreamOutput()) {
             out.setVersion(version);
             catShardsRequest.writeTo(out);