:bug: Link checker fails on Google Fonts preconnect URLs

[rubambiza]

Describe the bug

The link checker workflow fails with 3 errors, all from Google Fonts <link rel="preconnect"> tags in the rendered site HTML:

• https://fonts.googleapis.com (HTTP 404)
• https://fonts.gstatic.com (HTTP 404)

These are false positives — the link checker cannot validate bare preconnect domain hints (no path), so they always return 404 when fetched directly.

Steps To Reproduce

1. Run the link checker workflow on main
2. Observe 3 errors for fonts.googleapis.com and fonts.gstatic.com

Failing run: https://github.com/kagenti/.github/actions/runs/27223486800/job/80384287056

Expected Behavior

Link checker should skip known false-positive domains that are preconnect hints, not actual page links.

Fix

Add fonts\.googleapis\.com and fonts\.gstatic\.com patterns to skip_file.txt.