deps: Upgrade posthog-js to 1.405.2

[Ludy87]

Description of Changes

• Updated the frontend posthog-js dependency from ^1.268.0 to ^1.405.2.
• Refreshed frontend/package-lock.json and updated related PostHog transitive dependencies.
• Removed obsolete OpenTelemetry and protobuf-related transitive packages no longer required by the newer PostHog version.
• The existing PostHog APIs used by Stirling-PDF remain compatible.

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Checklist

General

• I have read the Contribution Guidelines
• I have read the Stirling-PDF Developer Guide (if applicable)
• I have read the How to add new languages to Stirling-PDF (if applicable)
• I have performed a self-review of my own code
• My changes generate no new warnings

Documentation

• I have updated relevant docs on Stirling-PDF's doc repo (if functionality has heavily changed)
• I have read the section Add New Translation Tags (for new translation tags only)

Translations (if applicable)

• I ran scripts/counter_translation.py

UI Changes (if applicable)

• Screenshots or videos demonstrating the UI changes are attached (e.g., as comments or direct attachments in the PR)

Testing (if applicable)

• I have run task check to verify linters, typechecks, and tests pass
• I have tested my changes locally. Refer to the Testing Guide for more details.

[github-actions]

📦 Tauri Desktop Builds Ready!

The desktop applications have been built and are ready for testing.

Download Artifacts:

🍎 macOS Universal: Download Stirling-PDF-macos-universal (.dmg) - 336.4 MB
🪟 Windows x64: Download Stirling-PDF-windows-x86_64 (.exe, .msi) - 262.2 MB

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Built from commit 2802894
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[stirlingbot]

✅ Frontend License Check Passed

All frontend licenses have been validated and no compatibility warnings were detected.

The frontend license report has been updated successfully.