Fix: image service warning

[luukbrauckmann]

Changes

Saw this warning in the console:

14:28:39 [WARN] [config] The adapter @astrojs/cloudflare has limited support for "sharp". Certain features may not work as expected.
14:28:39 [WARN] [adapter] Cloudflare does not support sharp. You can use the `compile` image service to compile images at build time. It will not work for any on-demand rendered images.

Moving the image service config to the adapter fixes this.

Associated issue

N.A.

How to test

Compare outputs:

This is where it occured to me: https://github.com/voorhoede/head-start/actions/runs/16499688786/job/46654533282#step:7:13

This has the fix: https://github.com/voorhoede/head-start/actions/runs/16499833417/job/46655076140#step:7:13

Checklist

• I have performed a self-review of my own code
• I have made sure that my PR is easy to review (not too big, includes comments)
• I have made updated relevant documentation files (in project README, docs/, etc)
• I have added a decision log entry if the change affects the architecture or changes a significant technology
• I have notified a reviewer