fix: add implicit-std = false to fix failing LSP test

[JoshuaBatty]

Description

The sync_with_updates_to_manifest_in_workspace test was failing because I forgot to specify implicit-std = false in the Forc.toml which meant it was trying to fetch when it shouldn't have.

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 #7116 will not alter performance

_{Comparing josh/fix_test (e716007) with master (7e1bc15)}

Summary

✅ 22 untouched benchmarks