[Bug] - REST GetObjectAttributes - Checksum retrieval stopped working

[lrm25]

Describe the bug
This may be related to #1001. The only updates to versitygw that could be responsible have been dependabot updates, so could be related to that.

When the checkum is asked for, direct to s3 returns:

<?xml version="1.0" encoding="UTF-8"?>
<GetObjectAttributesResponse xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Checksum><ChecksumSHA256>UJNd4Yi/Wadq+Vma0YOLQ2Aw6QwZNUfLr9YuU9HcJo0=</ChecksumSHA256><ChecksumType>FULL_OBJECT</ChecksumType></Checksum></GetObjectAttributesResponse>

versitygw is just returning an empty element:

<?xml version="1.0" encoding="UTF-8"?>
   <GetObjectAttributesResponse></GetObjectAttributesResponse>

To Reproduce

1. Start versitygw, e.g.: ./versitygw --access=******** --secret=******** --region=us-east-1 --iam-dir=/Users/lukemccrone/devel/versitygw/iam --cert /Users/lukemccrone/devel/versitygw/cert.pem --key /Users/lukemccrone/devel/versitygw/versitygw.pem posix --versioning-dir /tmp/versioning /tmp/gw
2. Create bucket, e.g.: aws --no-verify-ssl s3api create-bucket --bucket versity-gwtest-bucket-one-1
3. Add object to bucket with REST script, e.g.: curl -ks -w %{http_code} -X PUT https://localhost:7070/versity-gwtest-bucket-one-1/test_file -H Authorization: AWS4-HMAC-SHA256 Credential=********/20241226/us-east-1/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date;x-amz-checksum-sha256,Signature=2d6c560d66f6da708777d966456f02d4375d8b36e08d0860f320824dfb794778 -H x-amz-content-sha256: b4d1ec47eaf7d4107b00735ef5747e36ac7c5f8b6d6b72dfa3879a3176b1d8a8 -H x-amz-date: 20241226T165611Z -H x-amz-checksum-sha256: tNHsR+r31BB7AHNe9XR+Nqx8X4tta3Lfo4eaMXax2Kg= -T /Users/lukemccrone/devel/versitygw/versity-gwtest-files/test_file -o /Users/lukemccrone/devel/versitygw/versity-gwtest-files/result.txt
4. Attempt to get checksum attribute with REST script, e.g.: curl -ks -w %{http_code} https://localhost:7070/versity-gwtest-bucket-one-1/test_file?attributes= -H Authorization: AWS4-HMAC-SHA256 Credential=********/20241226/us-east-1/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date;x-amz-object-attributes,Signature=7a023593e851b512c9a344dd1ad2c1ab048487924f4198ee46d1b210cdc5ba1b -H x-amz-content-sha256: UNSIGNED-PAYLOAD -H x-amz-date: 20241226T165611Z -H x-amz-object-attributes: Checksum -o /Users/lukemccrone/devel/versitygw/versity-gwtest-files/attributes.txt

Expected behavior
Checksum reply resembles that of direct to s3.

Server Version
Version : v1.0.9
Build : bf20fa7
BuildTime: 2024-12-26_03:50:17PM
Darwin Lukes-MacBook-Pro.local 23.4.0 Darwin Kernel Version 23.4.0: Fri Mar 15 00:12:25 PDT 2024; root:xnu-10063.101.17~1/RELEASE_ARM64_T6030 arm64