[BUG]indices.forcemerge API spec is missing 'primary_only' param

[saimedhi]

What is the bug?
indices.forcemerge API spec is missing primary_only param. Param is recently introduced in PR. "primary_only" is available in OpenSearch 3.0+ versions.

Do you have any additional context?

• Fixes [BUG] 30_max_analyzed_offset failing opensearch-py#686 (comment)
• Related to yaml test https://github.com/opensearch-project/OpenSearch/blob/main/rest-api-spec/src/main/resources/rest-api-spec/test/indices.forcemerge/10_basic.yml#L32

[saimedhi]

@Xtansia, could you please check if this test is working as expected in opensearch-net? It will run for OpenSearch Main.

[Xtansia]

@Xtansia, could you please check if this test is working as expected in opensearch-net? It will run for OpenSearch Main.

The .NET YAML test runner uses the low-level client which allows setting arbitrary query params rather than using the explicitly specified properties. Rust on the other hand does some heuristics and skips tests that use APIs or params that don't yet exist in the client.