Allow renovate PR to have un committed changes (#630)

I've found CI always fails when renovate updates git submodule...
If there is un-committed changes by renovate PR(= new code will be
generated by openapi generator), I think we can allow this. Finally
github actions open PR after the PR by renovate is merged.

Another way is to make renovate to run script to generate code again,
but the cost is a little bit
high.(https://docs.renovatebot.com/configuration-options/#postupgradetasks)
The situation won't get bad even when we merge this change, so let me
merge this change.

.github/workflows/php-checks.yml

@@ -54,7 +54,7 @@ jobs:
           diff=$(git --no-pager diff --name-only HEAD)
           echo "DIFF_IS_EMPTY=$([[ -z "$diff" ]] && echo 'true' || echo 'false')" >> $GITHUB_ENV
           echo "CURRENT_DATETIME=$(date +'%Y%m%d%H%M%S')" >> $GITHUB_ENV
-      - if: ${{ env.DIFF_IS_EMPTY != 'true' }}
+      - if: ${{ env.DIFF_IS_EMPTY != 'true' && github.actor != 'renovate[bot]' }}
         run: |
           echo "There are changes from the auto-generated files by OAS. Please run diff-check.yml and merge the PR generated by it first."
           exit 1