Fix deprecation warning with usage of ast.Str

[Viicos]

Change Summary

Will be removed in 3.14

Related issue number

Checklist

• The pull request title is a good summary of the changes - it will be used in the changelog
• Unit tests for the changes exist
• Tests pass on CI
• Documentation reflects the changes where applicable
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

[codspeed-hq]

CodSpeed Performance Report

Merging #8837 will not alter performance

_{Comparing Viicos:deprecated-ast-str (1f22c55) with main (3dd3b42)}

Summary

✅ 10 untouched benchmarks

[alexmojaki]

@Viicos is this fine to merge?

[Viicos]

Sure