Use absolute paths for all download-artifact-verified calls

Convert all path arguments to download-artifact-verified action from
relative paths to absolute paths using ${{ github.workspace }}.
This complements the earlier commit for upload-artifact-verified.

Files updated:
- wstest.yml (6 downloads)
- release.yml (51 downloads)
- release-post-comment.yml (2 downloads)

Note: This work was completed with AI assistance (Claude Code).

Author: oberstet

.github/workflows/release-post-comment.yml

@@ -295,7 +295,7 @@ jobs:
           name: conformance-summary-quick
           run-id: ${{ steps.find-wstest.outputs.run_id }}
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          path: summary-artifact/
+          path: ${{ github.workspace }}/summary-artifact/
         continue-on-error: true
 
       - name: Get release notes from GitHub Release
@@ -473,7 +473,7 @@ jobs:
           name: conformance-summary-quick
           run-id: ${{ steps.find-wstest.outputs.run_id }}
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          path: summary-artifact/
+          path: ${{ github.workspace }}/summary-artifact/
         continue-on-error: true
 
       - name: Get release notes from GitHub Release