ci: only create Allure report for failing PRs [skip ci]

...that are not created by Renovate. This is to avoid unneccessary
changes added to the git history.

.github/workflows/check.yml

@@ -38,7 +38,7 @@ jobs:
   allure:
     # https://allurereport.org/docs/integrations-github/
     runs-on: ubuntu-latest
-    if: always() # even if tests fail
+    if: ${{ failure() && !startsWith(github.head_ref, 'renovate/') }}  # only if tests fail, but not for renovate changes
     needs: check
     concurrency:
       group: allure-${{ github.ref }}