github: fetch more PRs when triggering gitlab

By default, the API will fetch only 30 open PRs. This is enough currently
as we have 35 open ones. Bump the limit to the maximum. 100 should be enough
for some time. 🤞

Signed-off-by: Ondřej Budai <ondrej@budai.cz>

.github/workflows/trigger-gitlab.yml

@@ -34,6 +34,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           route: GET /repos/${{ github.repository }}/pulls
+          per_page: 100
 
       - name: Checkout branch
         run: |