Check for unsupported HEAD before failing request

[motz0815]

Closes #549

This is a new approach to handling failing HEAD requests, derived from the discussion in #550

Basically, this PR re-orders the conditional failing of a request if the HEAD fetching did not work as expected. For example, presigned S3 URLs do not support HEAD requests and respond with a 403.

Also, isHeadUnsupportedResponse now returns true as well when the HEAD response was a 403. (to gracefully handle the before mentioned).

Testing with the following URL (expiring on May 5th) now works as expected (also determining the right filename):

Details

https://nbg1.your-objectstorage.com/ziffer-artifacts-staging/builds/4e8f7980-3955-48c4-9ff9-9a8dbedcbf41/test-plugin-1.0-SNAPSHOT.jar?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=6OL4X4U2SMEH6AKWA71D/20250428/auto/s3/aws4_request&X-Amz-Date=20250428T135531Z&X-Amz-Expires=604800&X-Amz-SignedHeaders=host&X-Amz-Signature=0832406b9351cda79525911df41b7f76166993eb0949e9ab4135cd07c904c64a

instead of failing the request early because a HEAD on this URL returns 403.

[itzg]

Thanks for the follow up!

[itzg]

This is now included in the latest itzg/minecraft-server image build.