Add run attempt to WORKFLOW_URL for reporting failed tests (#513)

Required:

Task/Issue URL: https://app.asana.com/0/1203301625297703/1205561819790003/f
iOS PR: duckduckgo/iOS#2034
macOS PR: duckduckgo/macos-browser#1671
What kind of version bump will this require?: None

Steps to test this PR:
See this Asana task and verify that it contains a valid URL to a specific attempt of a workflow run.

.github/workflows/pr.yml

@@ -73,7 +73,7 @@ jobs:
         if: always() # always run even if the previous step fails
         env:
           ASANA_ACCESS_TOKEN: ${{ secrets.ASANA_ACCESS_TOKEN }}
-          WORKFLOW_URL: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
+          WORKFLOW_URL: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}/attempts/${{ github.run_attempt }}
         run: |
           # Extract failed tests from the junit report
           # Only keep failures unique by classname and name (column 1 and 2 of the yq output)