chore(deps): update actions/upload-artifact action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -55,7 +55,7 @@ jobs:
       run: msbuild build.build -t:All -p:Version=$env:BUILD_VERSION -p:WIX_PATH=$env:wix -p:NUnitConsoleRunnerPath=$env:GITHUB_WORKSPACE\packages\nunit.consolerunner\3.15.0\
 
     - name: Upload a Build Artifact
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: 'Test Result'
         path: Build\_build\TestResult.html