AWS SDK PHP v3.339.0+ introduced a breaking change requiring the Content-MD5
header for DeleteObjects operations. This causes 'MissingContentMD5' errors when
using S3-compatible services like MinIO.
Add middleware to automatically calculate and inject the Content-MD5 header on
all DeleteObjects requests. This is applied universally at the S3ConnectionTrait
level, fixing both external storage (AmazonS3) and core ObjectStore (S3) classes.
Fixes: https://github.com/aws/aws-sdk-php/issues/3068
Signed-off-by: John Molakvoæ (skjnldsv) <skjnldsv@protonmail.com>
