Bump opensearch-py from 2.5.0 to 2.8.0

Bumps [opensearch-py](https://github.com/opensearch-project/opensearch-py) from 2.5.0 to 2.8.0.
- [Release notes](https://github.com/opensearch-project/opensearch-py/releases)
- [Changelog](https://github.com/opensearch-project/opensearch-py/blob/main/CHANGELOG.md)
- [Commits](opensearch-project/opensearch-py@v2.5.0...v2.8.0)

---
updated-dependencies:
- dependency-name: opensearch-py
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -9,7 +9,7 @@ google-auth==2.29.0
 google-auth-httplib2==0.2.0
 google-auth-oauthlib==1.2.0
 googleapis-common-protos==1.63.0
-opensearch-py==2.5.0
+opensearch-py==2.8.0
 pandas==2.2.2
 sqlalchemy==1.4.*
 psycopg2==2.9.9