ci: don't run screenshot job on self-hosted runner

Author: jnsgruk

.github/workflows/release-to-candidate.yml

@@ -62,11 +62,11 @@ jobs:
     name: 📸 Gather screenshots
     needs: call-for-testing
     environment: "Candidate Branch"
-    runs-on: self-hosted
+    runs-on: ubuntu-latest
     steps:
       - name: 📸 Gather screenshots
         uses: snapcrafters/ci/get-screenshots@main
         with:
           issue-number: ${{ needs.call-for-testing.outputs.issue-number }}
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          screenshots-token: ${{ secrets.SNAPCRAFTERS_BOT_COMMIT }}
+          screenshots-token: ${{ secrets.SNAPCRAFTERS_BOT_COMMIT }}