fix: better s3source for pmtiles

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 12.82051% with 34 lines in your changes missing coverage. Please review.

Project coverage is 58.76%. Comparing base (83cc6f7) to head (8bd5e9b). Report is 5 commits behind head on main.

Files	Patch %	Lines
src/source/pmtiles.ts	12.82%	34 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #104 +/- ## ========================================== - Coverage 59.49% 58.76% -0.74% ========================================== Files 19 19 Lines 1459 1484 +25 Branches 92 92 ========================================== + Hits 868 872 +4 - Misses 588 609 +21 Partials 3 3 ```

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