Add .NET 10.0 target framework support to all projects and CI workflow

[Copilot]

Overview

This PR adds .NET 10.0 target framework support to all project files and updates the GitHub Actions CI workflow to build and test against .NET 10.0, preparing the repository for the upcoming .NET 10.0 release (expected November 2025).

Changes Made

Project Files

All four .csproj files have been updated to multi-target both net8.0 and net10.0:

• PdfAValidator/PdfAValidator.csproj - Main library project
• PdfAValidatorWebApi/PdfAValidatorWebApi.csproj - Web API project
• PdfAValidatorTest/PdfAValidatorTest.csproj - Unit test project
• PdfAValidatorWebApiTest/PdfAValidatorWebApiTest.csproj - Integration test project

Each project now uses:

<TargetFrameworks>net8.0;net10.0</TargetFrameworks>

GitHub Actions Workflow

Updated .github/workflows/dotnet.yml to install both .NET 8.0.x and 10.0.x SDKs in all four jobs:

• build - Cross-platform build and test on Ubuntu, macOS, and Windows
• deployRelease - Release deployment to NuGet and GitHub
• deployTest - Test deployment to NuGet test feed
• deployAzure - Azure Web App deployment

The setup-dotnet action now uses:

- name: Setup .NET
  uses: actions/setup-dotnet@v4
  with:
    dotnet-version: |
      8.0.x
      10.0.x

Benefits

• Future-Ready: Once .NET 10.0 SDK is released, builds and tests will automatically run against both .NET 8.0 and 10.0
• Backward Compatibility: Maintains support for .NET 8.0 while adding .NET 10.0
• No Breaking Changes: Existing .NET 8.0 consumers can continue using the library without any changes
• CI Coverage: GitHub Actions will verify compatibility with both target frameworks once .NET 10.0 is available

Note

.NET 10.0 is expected to be released in November 2025. These changes prepare the codebase in advance. The projects will continue to build successfully with .NET 8.0 until .NET 10.0 SDK becomes available.

Original prompt

Update all project files in the repository to add net10.0 to the TargetFrameworks or TargetFramework property, if not already present. Also, update any GitHub Actions workflow files (e.g., .github/workflows/build.yml) to include .NET SDK version 10.0.x in the build matrix or setup-dotnet steps, ensuring CI builds and tests for .NET 10 as well. Make these updates for all mainline projects and the primary CI build workflow.

This pull request was created as a result of the following prompt from Copilot chat.

Update all project files in the repository to add net10.0 to the TargetFrameworks or TargetFramework property, if not already present. Also, update any GitHub Actions workflow files (e.g., .github/workflows/build.yml) to include .NET SDK version 10.0.x in the build matrix or setup-dotnet steps, ensuring CI builds and tests for .NET 10 as well. Make these updates for all mainline projects and the primary CI build workflow.

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[github-actions]

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I have read the CLA Document and I hereby sign the CLA

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