fix: Catch expected NotFoundException

[kesselb]

Summary

The method was catching the wrong exception.

• Create public share link for a folder
• Copy the share token
• Send http request like below (set dir to a value that wont exist)
• 💥

POST https://server99.internal/index.php/apps/files_sharing/shareinfo?dir=test123
Content-Type: application/x-www-form-urlencoded

t=share_token

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI