Bump actions/download-artifact from 4 to 6 (#1967)

Author: dependabot[bot]

.github/workflows/package.yml

@@ -109,7 +109,7 @@ jobs:
            run: dotnet tool install --global NuGetKeyVaultSignTool
 
          - name: Download Unsigned Packages
-           uses: actions/download-artifact@v4
+           uses: actions/download-artifact@v6
            with: 
                 name: Unsigned
                 path: '${{ github.workspace }}/unsigned' 
@@ -166,7 +166,7 @@ jobs:
          - name: Install .NET Core
            uses: actions/setup-dotnet@v4
          - name: Download Packages
-           uses: actions/download-artifact@v4
+           uses: actions/download-artifact@v6
            with: 
                 name: Signed
                 path: '${{ github.workspace }}/packages'