Fix: detect duplicate languages in tooling data

[Vishv04]

What kind of change does this PR introduce?
Feature - Adds case-insensitive unique validation for language entries
Bug fix - remove two entries of same name such as 'JavaScript' and 'Javascript'

Issue Number:

• Closes 🐛 Bug: Two JavaScript labels for filter on Tools page #1443
• Related to #___
• Others?

Screenshots/videos:
Forcefully made mistakes in the name of language,

Validator finds the mistake,

If relevant, did you update the documentation?

Summary
This PR introduces case-insensitive unique validation for language entries in the tooling data to solve several existing problems:

1. Inconsistent language casing across tools (e.g., "JavaScript" vs "javascript" vs "JAVASCRIPT")
2. Potential confusion for users seeing the same language listed multiple times

My solution:
Implements a custom AJV keyword caseInsensitiveUnique that:

• Detects and reports case-insensitive duplicates using set
• Provides clear error messages for easy fixes

For Tool Maintainers:

# Before
languages:
  - "JavaScript"
  - "javascript"
  - "Python"
  - "PYTHON"

# After
languages:
  - "JavaScript"  # Use consistent casing from schema enum
  - "Python"

Does this PR introduce a breaking change?

• Existing tools with multiple case variants of the same language will fail validation

[github-actions]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (219521e) to head (8caf38b).

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files           10        10           
  Lines          396       396           
  Branches       106       106           
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  Hits           396       396           

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[Vishv04]

Hi @benjagm @jdesrosiers @DhairyaMajmudar,
I kindly request you to review this PR at your convenience and share your feedback. Thank you!