feat: Migrate deploy to Bunny and revamp CI

[Stensel8]

Summary

Replaced the GitHub Pages workflow with a Bunny.net deploy pipeline and centralized Hugo setup in a new action. This ensures better consistency across my repo's.

Type of change

• feat — new page or feature

PR title and commit types must follow these standards — view the contributing guide

Checklist

• PR title follows the commit convention (e.g. fix: correct nmcli command in eduroam guide)
• Both EN and NL versions updated (if applicable)
• Media is in AVIF format (not PNG/JPG)
• No broken image references (/images/*.avif all exist in static/images/)
• Tested locally with hugo server

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