chore(deps): update danielpalme/reportgenerator-github-action action to v5.1.21 (#994)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -54,7 +54,7 @@ jobs:
           name: Code coverage macos-latest
           path: coverage-macos
       - name: Generate coverage report
-        uses: danielpalme/[email protected].20
+        uses: danielpalme/[email protected].21
         with:
           reports: "**/coverage.cobertura.xml"
           targetdir: "coverage-report"