Fix versions for 2.x on main (#8846)

Signed-off-by: Kunal Kotwani <kkotwani@amazon.com>

Author: kotwanikunal

CHANGELOG.md

@@ -103,4 +103,4 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Security
 
 [Unreleased 3.0]: https://github.com/opensearch-project/OpenSearch/compare/2.x...HEAD
-[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.8...2.x
+[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.10...2.x

README.md

@@ -7,7 +7,7 @@
 [![Security Vulnerabilities](https://img.shields.io/github/issues/opensearch-project/OpenSearch/security%20vulnerability?labelColor=red)](https://github.com/opensearch-project/OpenSearch/issues?q=is%3Aissue+is%3Aopen+label%3A"security%20vulnerability")
 [![Open Issues](https://img.shields.io/github/issues/opensearch-project/OpenSearch)](https://github.com/opensearch-project/OpenSearch/issues)
 [![Open Pull Requests](https://img.shields.io/github/issues-pr/opensearch-project/OpenSearch)](https://github.com/opensearch-project/OpenSearch/pulls)
-[![2.8 Open Issues](https://img.shields.io/github/issues/opensearch-project/OpenSearch/v2.8.0)](https://github.com/opensearch-project/OpenSearch/issues?q=is%3Aissue+is%3Aopen+label%3A"v2.8.0")
+[![2.10 Open Issues](https://img.shields.io/github/issues/opensearch-project/OpenSearch/v2.10.0)](https://github.com/opensearch-project/OpenSearch/issues?q=is%3Aissue+is%3Aopen+label%3A"v2.10.0")
 [![3.0 Open Issues](https://img.shields.io/github/issues/opensearch-project/OpenSearch/v3.0.0)](https://github.com/opensearch-project/OpenSearch/issues?q=is%3Aissue+is%3Aopen+label%3A"v3.0.0")
 [![GHA gradle check](https://github.com/opensearch-project/OpenSearch/actions/workflows/gradle-check.yml/badge.svg)](https://github.com/opensearch-project/OpenSearch/actions/workflows/gradle-check.yml)
 [![GHA validate pull request](https://github.com/opensearch-project/OpenSearch/actions/workflows/wrapper.yml/badge.svg)](https://github.com/opensearch-project/OpenSearch/actions/workflows/wrapper.yml)