fix fallback compilation on new encoding

[xunilrj]

Description

When running tests in contracts with the fallback function, we get an error with the __log intrinsic. The issue is that we needlessly compile the fallback function twice. And in some cases (numeric decay), the __log argument would return a TypeId that was not collected in the collect_metadata phase.

29 | 
30 |     use std::call_frames::*;
31 |     __log(3);
   |     ^^^^^^^^ Internal compiler error: Unable to determine ID for log instance.
Please file an issue on the repository and include the code that triggered this error.
32 |     __log(called_method());
33 |     __log("double_value");
   |
____

This was never caught because we only compile sdk-harness tests, we never run their unit tests in the CI. Which this PR is also doing.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #6998 will not alter performance

_{Comparing xunilrj/fix-fallback-compilation (97e671e) with master (d46f08a)}

Summary

✅ 22 untouched benchmarks