fix: mention invalid string in warning message

[joseph-sentry]

the current warning message isn't clear so i'm adding in the invalid string and trying to clarify the message in general

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 6 lines in your changes missing coverage. Please review.

Project coverage is 95.59%. Comparing base (f4f44a3) to head (61b32a2).
Report is 2 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/junit.rs	54.54%	5 Missing ⚠️
src/raw_upload.rs	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #81      +/-   ##
==========================================
- Coverage   95.78%   95.59%   -0.19%     
==========================================
  Files          17       17              
  Lines        2038     2043       +5     
==========================================
+ Hits         1952     1953       +1     
- Misses         86       90       +4     

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[codspeed-hq]

CodSpeed Performance Report

Merging #81 will not alter performance

_{Comparing joseph/fix-message (61b32a2) with main (f4f44a3)}

Summary

✅ 6 untouched benchmarks

[codecov-notifications]

Codecov Report

Attention: Patch coverage is 66.66667% with 6 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/junit.rs	54.54%	5 Missing ⚠️
src/raw_upload.rs	66.66%	1 Missing ⚠️

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[Swatinem]

I would truncate this to a more reasonable length:

Suggested change

	return Err(ValidatedStringError::StringTooLong(value));
	let pos = value.floor_char_boundary(80);
	value.truncate(pos);
	return Err(ValidatedStringError::StringTooLong(value));

Note that floor_char_boundary is not stable yet, but its quite reasonable to just copy-paste the code from core: https://doc.rust-lang.org/src/core/str/mod.rs.html#407

… or rather do that truncation later on when printing the error, and then also quote / ellipsize the string as well.