Retarget projects and workflows to .NET 10

[Copilot]

This updates the repository’s build target from .NET 9 to .NET 10 across the library, test project, tooling, and GitHub Actions. It also aligns package dependencies and metadata with the new target without broadening scope beyond the retarget.

• Project targeting

  • Retargets all SDK-style projects to net10.0:
    • NetCore.Utilities
    • NetCore.Utilities.Tests
    • EncryptionKeyGenerator

• Dependency alignment

  • Moves Microsoft.Extensions.* references used by the library and tests to 10.0.0
  • Updates Microsoft.SourceLink.GitHub to the .NET 10 line to keep package/build metadata aligned with the new target

• CI/CD

  • Updates GitHub Actions workflows to install and build with .NET 10.0.x
  • Keeps existing workflow structure and release flow unchanged

• Documentation and package metadata

  • Refreshes README/package description text where needed while keeping wording version-neutral to avoid stale framework-specific claims

<PropertyGroup>
  <TargetFramework>net10.0</TargetFramework>
</PropertyGroup>

- uses: actions/setup-dotnet@v6
  with:
    dotnet-version: 10.0.x

• Fixes Update Project to Target .NET 10 #96

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud