chore!: update dotnet 10

[Soap-141]

GitHub Issue: #

Proposed Changes

• Bug fix
• Feature
• Code style update (formatting)
• Refactoring (no functional changes, no api changes)
• Build or CI related changes
• Documentation content changes
• Other, please describe:

Description

Now targets .NET 10 and Uno 6.
Dropped Support of Mac OS in favour of Mac Catalyst.
Dropped support for Xamarin.

Impact on version

• Major (Public API was modified.)
  • Public constructs (class, struct, delegate, enum, etc.) were removed or renamed.
  • Public members were removed or renamed.
  • Public method signatures were changed or renamed.
• Minor (Public API was extended.)
  • Public constructs, members, or overloads were added.
• Patch (Public API was unchanged.)
  • A bug in behavior was fixed.
  • Documentation was changed.
• None (The library is unchanged.)
  • Only code under the build folder was changed.
  • Only code under the .github folder was changed.

PR Checklist

• Your conventional commits are aligned with the Impact on version section.
• Documentation is up to date.
  • Content of README.md is up to date.
  • XML documentation is up to date.
• The BREAKING_CHANGES.md document is up to date.
  • Create a new Major.0.0 header if you do a Major change and list the breaking changes.
• Tested on all relevant platforms

Other information

Internal Issue (If applicable):

[Copilot]

Pull request overview

This PR updates the project from .NET 8 to .NET 10, along with related dependency and tooling updates. The changes include upgrading the target framework, language version, NuGet packages, build agent, and CI/CD configuration to support the new .NET version.

Changes:

• Target framework updated from net8.0 to net10.0 across all platforms
• Language version updated from 12.0 to 14.0
• Build infrastructure updated to use .NET 10 SDK and windows-2025 agent

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/GeolocatorService.Uno.WinUI/GeolocatorService.Uno.WinUI.csproj	Updates target frameworks to net10.0, upgrades dependencies, and changes macOS to Mac Catalyst
build/stage-build.yml	Replaces manual workload installation with uno-check tooling for .NET 10
build/azure-pipelines.yml	Updates Windows build agent to windows-2025
BREAKING_CHANGES.md	Documents breaking changes for version 4.0.x

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