fix(vercel-edge): fix route generation

[smaeda-ks]

It seems routeRules generates invalid routes when using the vercel-edge preset.

This is because nitro only creates pretender functions for the vercel preset:
https://github.com/unjs/nitro/blob/4585ca856b0fb4d5601e30fc36f9dbde4aef03de/src/presets/vercel.ts#L51-L85

and the generateEndpoint function isn't considering the vercel-edge preset:
https://github.com/unjs/nitro/blob/4585ca856b0fb4d5601e30fc36f9dbde4aef03de/src/presets/vercel.ts#L226-L234

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 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)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

📝 Checklist

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

[codecov]

Codecov Report

Merging #1071 (649f418) into main (7ae95d2) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1071      +/-   ##
==========================================
- Coverage   67.32%   67.32%   -0.01%     
==========================================
  Files          62       62              
  Lines        6292     6295       +3     
  Branches      707      709       +2     
==========================================
+ Hits         4236     4238       +2     
  Misses       2042     2042              
- Partials       14       15       +1     

Impacted Files	Coverage Δ
src/presets/vercel.ts	76.79% <100.00%> (-0.13%)	⬇️

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[pi0]

Thanks 💯