feat(no-in-array): Disallow using in operator for arrays

[mahdi-farnia]

PR Checklist

• Addresses an existing open issue: fixes Rule proposal: Ban 'in' operator for arrays  #5474
• That issue was marked as accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Before:
Error expected because in operator can't be used for checking array values.

const array = [4, 5, 6];

if(4 in array) {
  // ...
}

After:

const array = [4, 5, 6];
// vvv Error: 'in' operator for arrays is forbidden. Use array.indexOf or array.includes instead.
if(4 in array) {
  // ...
}

Closes: #5474

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[mahdi-farnia]

I have opened another pull request here: #5848

And that PR history comes here too! (I'm not really experienced using github & git)

This shouldn't cause a problem. (should it?)

[codecov]

Codecov Report

Merging #5851 (4e9da68) into main (733b359) will increase coverage by 0.00%.
The diff coverage is 92.85%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5851   +/-   ##
=======================================
  Coverage   91.35%   91.35%           
=======================================
  Files         361      363    +2     
  Lines       12024    12066   +42     
  Branches     3499     3513   +14     
=======================================
+ Hits        10984    11023   +39     
  Misses        743      743           
- Partials      297      300    +3     

Flag	Coverage Δ
unittest	91.35% <92.85%> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
.../eslint-plugin/src/rules/call-super-on-override.ts	90.32% <90.32%> (ø)
packages/eslint-plugin/src/rules/no-in-array.ts	100.00% <100.00%> (ø)

[JoshuaKGoldberg]

We don't mind messy Git histories! The commits all get squash merged down to a single merge commit anyway. Git can be excruciatingly difficult system to use for new developers; requiring rewriting history for clean commits is IMO an exclusionary practice.

Can you just delete the unrelated files from this branch? Each PR should only have files that relate to it.

[JoshuaKGoldberg]

Also, sorry for the redirect @mahdi-farnia - we realized later on that no-in-array is really a subset of what no-misused-in would cover (#5677). I'm going to close this PR for now, but feel free to send a new one that covers no-misused-in overall.