chore: increase stale bot limit to 300

[Hebilicious]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

So far :

18 issues have been closed by the reproduire-close workflow : https://github.com/nuxt/nuxt/issues?q=is%3Aissue+sort%3Aupdated-desc+label%3Aclosed-by-bot+is%3Aclosed 🎉

Looking at the latest run, https://github.com/nuxt/nuxt/actions/runs/5791807546/job/15697183387, 366 items were processed.
Increasing by 3x means we should be able to process every item in one run, without hitting the rate limit (which should be 1000 operations)

Any suggestions to improve the bot would be welcome 🙏🏽

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

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