Retire .NET 9 and prepare for .NET 11

[Copilot]

Retires .NET 9 support, modernizes the SDK/CI baseline, and updates dependencies for a clean path to .NET 11.

Changes

• Framework support

  • Target .NET 10 exclusively.
  • Remove .NET 9 package conditions and compatibility rules.
  • Add SDK feature-band configuration with stable roll-forward behavior.

• Dependencies

  • Upgrade direct NuGet dependencies to compatible stable releases.
  • Remediate the vulnerable transitive Microsoft.OpenApi version.
  • Remove unused package and project references.
  • Adapt API versioning and OpenAPI registration for upgraded packages.

• CI and documentation

  • Remove .NET 9 from CI and update first-party GitHub Actions.
  • Document the .NET 10 support policy, .NET 9 retirement, and planned .NET 11 adoption.

• Fixes Prepare .NET 11 support, retire .NET 9, and upgrade dependencies #75

[mathieumack]

Seems good, to be tested now

[mathieumack]

@copilot : Please add unit tests for each package.
You can use azurite for storage emulator or cosmos emulator for local services

[Copilot]

@copilot : Please add unit tests for each package.
You can use azurite for storage emulator or cosmos emulator for local services

Added focused unit tests for all four packages in commit 3ab65c6. They use in-process framework/SDK types and fake credentials, so Azurite/Cosmos emulators are not needed. All 6 tests, build, pack, vulnerability, and deprecation checks pass.

[mathieumack]

I will test it manually