Bump dawidd6/action-download-artifact from 2 to 6 in /.github/workflows

Bumps [dawidd6/action-download-artifact](https://github.com/dawidd6/action-download-artifact) from 2 to 6.
- [Release notes](https://github.com/dawidd6/action-download-artifact/releases)
- [Commits](dawidd6/action-download-artifact@v2...v6)

---
updated-dependencies:
- dependency-name: dawidd6/action-download-artifact
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/release-nuget.yml

@@ -16,15 +16,15 @@ jobs:
     steps:
     - name: Download specific artifact
       if: ${{ github.event.inputs.runId > 0 }}
-      uses: dawidd6/action-download-artifact@v2
+      uses: dawidd6/action-download-artifact@v6
       with:
         workflow: build.yml
         branch: main
         run_id: ${{ github.event.inputs.runId }}
 
     - name: Download latest artifact
       if: ${{ github.event.inputs.runId == -1 }}
-      uses: dawidd6/action-download-artifact@v2
+      uses: dawidd6/action-download-artifact@v6
       with:
         workflow: build.yml
         branch: main