fix: Arduino Preprocess should always run if the target file is missing

[cmaglie]

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What kind of change does this PR introduce?

This is a regression introduced in #3112, but not yet released.

What is the current behavior?

If an error occurs during Arduino preprocessing, the preprocessed sketch is not generated, and the error is displayed.

By the way, if another compile happens immediately without changing the sketch, the Arduino Preprocessing is skipped because the sketch is "unchanged." As a result, the previously displayed error is no longer shown, and the compile continues, leading to another unrelated error (probably "missing setup" or "missing loop" because the preprocessed sketch hasn't been generated).

What is the new behavior?

If the preprocessed sketch hasn't been created, the Arduino Preprocessor is always executed, even if the sketch is unchanged.

Does this PR introduce a breaking change, and is titled accordingly?

Other information

[codecov]

Codecov Report

❌ Patch coverage is 84.61538% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 69.38%. Comparing base (da1d3eb) to head (e1b5cb9).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
...rnal/arduino/builder/internal/detector/detector.go	33.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3149      +/-   ##
==========================================
+ Coverage   69.36%   69.38%   +0.02%     
==========================================
  Files         252      252              
  Lines       19422    19505      +83     
==========================================
+ Hits        13472    13534      +62     
- Misses       4706     4714       +8     
- Partials     1244     1257      +13     

Flag	Coverage Δ
unit	69.38% <84.61%> (+0.02%)	⬆️

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