scraping fails when a scraping PR is pending

[cuihtlauac]

Scraping takes place every day. If things needs to be added a PR is created. If the PR isn't merged and scraping finds a different set of changes the next day, it will attempt to create a new PR and fail.

See: https://github.com/ocaml/ocaml.org/actions/workflows/scrape.yml

• Scrape #768 pass, create PR Update scraped data #2106
• Scrape #769 fail
• Scrape #770 fail
• Scrape #771 fail
• Scrape #772 fail
• Merge PR Update scraped data #2106
• Scrape #773 pass, creates PR Update scraped data #2129