Fix LibraryThing false negatives with Cloudflare bypass

[jake112-AO]

Problem

LibraryThing was returning false negatives (failing to find existing users) because the site uses Cloudflare bot protection that blocks standard HTTP requests.

Testing

• Real user test: FlorenceArt - Now correctly detected
• Fake user test: asdkjfhakjsdhf123456789 - Correctly returns "not found"
• Regression test: Other sites still work normally

Solution

• Added cloudscraper library to bypass Cloudflare challenges
• Implemented useCloudScraper flag in site configuration
• Modified session creation to conditionally use cloudscraper
• Updated LibraryThing configuration in data.json

Changes

• sherlock_project/sherlock.py: Added cloudscraper import and conditional session creation
• sherlock_project/resources/data.json: Added "useCloudScraper": true to LibraryThing
• pyproject.toml: Added cloudscraper dependency

Notes

• This change is backward compatible - existing sites continue to use requests
• Only sites with "useCloudScraper": true will use cloudscraper
• Other sites with Cloudflare protection can now use this same approach

[github-actions]

Automatic validation of changes

Target	F+ Check	F- Check
LibraryThing	❌   Fail	❌   Fail

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Failures were detected on at least one updated target. Commits containing accuracy failures will often not be merged (unless a rationale is provided, such as false negatives due to regional differences).