Store str instead of String in ParseError

[DaniPopes]

Minor performance improvement for the parser. In repeat_until_end_paren the Err is constructed and discarded immediately after, which allocated a string unnecessarily.

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #469 will not alter performance

_{Comparing DaniPopes:parse-error-string (4031ed9) with main (2c8d947)}

Summary

✅ 8 untouched benchmarks