ci: temporarily pin Dio in tests to a version that works with WASM

[vaind]

The CI is currently broken because of Dio making a breaking change regarding WASM compatibility without a major version bump (See cfug/dio#2266 for some details.)

Currently, we cannot make a release because tests started to fail after the latest version was picked up in CI. We don't want to change the dependency constraint because most users aren't using WASM compilation so we don't want to prevent them from updating Dio. Pinning in tests to a lower version works fine.

💚 How did you test it?

CI passes

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.04%. Comparing base (d20b867) to head (4faf42a).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2145      +/-   ##
==========================================
+ Coverage   88.25%   95.04%   +6.79%     
==========================================
  Files         215        9     -206     
  Lines        7515      202    -7313     
==========================================
- Hits         6632      192    -6440     
+ Misses        883       10     -873     

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[AlexV525]

We've published Dio v5.5.0+1 to solve the issue.

[buenaflor]

ci looks fine, guess we don't need this pr anymore