Splatoon 3 Stages/Challenges: Add new stages

[MarkGamed7794]

Adds images for the two regular stages and one Salmon Run stage that have been added to the game since then on both my Splatoon 3 apps.

[tidbyt[bot]]

⚠️ The automated review process is experimental and likely has bugs. Please bear with us as we iron out the kinks and enable you to ship changes at high velocity 🚀

Next Steps

Hello! Thank you so much for your change 🤜 🤛 . There are a few things you need to do:

• [ ] Sign the CLA if you haven't already
• [ ] Ensure your build is green! Any problem will display a proposed solution to try out
• [ ] Get a review, either by Tidbyt Bot or by a Tidbyt engineer

  Manual Review Required

  Hang tight! A Tidbyt engineer will be by shortly to review your change. Here is what they will be looking for:		Test	Details
  🟡	App Dir	Touches files in multiple directories
  🟡	Modules	Multiple .star files: apps/splat3challenges/splat3_challenges.star, apps/splatoon3stages/splatoon_3_stages.star
  ✅	Original Author	The original author matches the PR author