Upgrade NuGet packages to latest versions

[Copilot]

This PR upgrades all NuGet packages to their latest stable versions to improve security, performance, and compatibility.

Key Changes

Orleans Framework (8.2.0 → 9.2.1)

• Major version upgrade bringing performance improvements and bug fixes
• Updated across all projects: Microsoft.Orleans.Sdk, Microsoft.Orleans.Runtime, Microsoft.Orleans.Core, Microsoft.Orleans.Reminders, Microsoft.Orleans.Client, Microsoft.Orleans.Persistence.Memory, Microsoft.Orleans.TestingHost

OpenTelemetry (1.9.0 → 1.12.0)

• Updated to latest stable version for improved telemetry and metrics collection

Test Framework Dependencies

• Microsoft.NET.Test.Sdk: 17.10.0 → 17.14.1
• xunit: 2.9.0 → 2.9.3
• xunit.runner.visualstudio: 2.8.2 → 3.1.4

Performance Testing

• BenchmarkDotNet: 0.13.12 → 0.15.4
• Microsoft.CodeAnalysis.Common: 4.10.0 → 4.14.0 (fixes version conflict)

Testing

• ✅ All 22 unit tests pass
• ✅ Full solution builds successfully
• ✅ Orleans Dashboard functionality verified by running test host
• ✅ HTTP endpoints respond correctly (verified with curl)
• ✅ No breaking changes introduced

The upgrade maintains full backward compatibility while bringing the project up to the latest stable versions of its dependencies. One minor transitive dependency warning remains from BenchmarkDotNet but doesn't affect functionality.

Original prompt

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This section details on the original issue you should resolve

<issue_title>upgrade nuget packages</issue_title>
<issue_description></issue_description>

<agent_instructions>do not upgrade npm packages at this time</agent_instructions>

Comments on the Issue (you are @copilot in this section)

Fixes #443

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