fix(eslint-plugin): [no-unnecessary-condition] properly reflect multiple negations in message

[abrahamguo]

PR Checklist

• Addresses an existing open issue: fixes Bug: [no-unnecessary-condition] rule message is incorrect for multiple negations #9939
• That issue was marked as accepting prs
• Steps in Contributing were taken

Overview

Properly reflect the truthiness or falsiness of a value after multiple negations, and expand the reporting range to include the negation operator(s).

[typescript-eslint]

Thanks for the PR, @abrahamguo!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.69%. Comparing base (4d31ebe) to head (493870e).
Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9940      +/-   ##
==========================================
+ Coverage   86.00%   88.69%   +2.68%     
==========================================
  Files         425      425              
  Lines       14810    14811       +1     
  Branches     4308     4309       +1     
==========================================
+ Hits        12738    13136     +398     
+ Misses       1723     1531     -192     
+ Partials      349      144     -205     

Flag	Coverage Δ
unittest	88.69% <100.00%> (+2.68%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...slint-plugin/src/rules/no-unnecessary-condition.ts	99.04% <100.00%> (+0.48%)	⬆️

... and 103 files with indirect coverage changes

[JoshuaKGoldberg]

🧹 ✨