Update GitHub Actions workflow to use current versions

- Update actions/upload-artifact from v2 to v4 (fixes deprecation warning)
- Update actions/checkout from v1 to v4
- Update actions/setup-dotnet from v1 to v4 with .NET 8.0.x

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: thecoderok

.github/workflows/release-tag.yml

@@ -12,17 +12,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v4
       - name: Setup .NET Core
-        uses: actions/setup-dotnet@v1
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '8.0.x'
       - name: Build
         run: dotnet build -c Release
       - name: Tests
         run: dotnet test -c Release --no-build
       - name: Pack artifacts
         run: dotnet pack src -c Release  --no-build -o artifacts/
       - name: Collect artifacts
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: nupkg
           path: artifacts/