OpenSearch dependencies block trim validation

[HavenDV]

autosdk trim src/OpenSearch/src/LangChain.Databases.OpenSearch.csproj still fails after the repository's own IL2091 warning was fixed in 2108a24. The remaining warnings originate in the referenced packages:

• OpenSearch.Client 2.2.0: IL2104, assembly produced trim warnings.
• OpenSearch.Net 2.2.0: IL2104, assembly produced trim warnings.

The OpenSearch project builds, and the integration test suite passes (26/26). The repository code now preserves the public parameterless constructor needed by Activator.CreateInstance<TRecord>().

Investigate the underlying linker diagnostics and a supported OpenSearch client version or an AOT-compatible transport. Keep the trim check failing until the package warnings are resolved; suppressing IL2104 would hide a real NativeAOT risk.

[HavenDV]

Fresh 2026-10-01 validation: dotnet list package --outdated and --vulnerable found no compatible updates or vulnerabilities; OpenSearch.Client 2.2.0 is current. autosdk trim --verbose still reports IL2104 for OpenSearch.Client and OpenSearch.Net. An isolated publish with TrimmerSingleWarn=false expanded this to 609 individual warnings (498 OpenSearch.Client, 109 OpenSearch.Net, 2 others), dominated by reflection-based JSON serialization. Upstream OpenSearch .NET AOT support is tracked at opensearch-project/opensearch-net#424. Suppressing IL2104 would hide a real compatibility gap; this issue remains open pending an AOT-safe client/transport path.