As reported in https://github.com/localstack/localstack/issues/6659#issuecomment-1630932643_, `HeadObject` does not respect `ChecksumMode`. 


```shell
at 09:31:57 ➜ AWS_DEFAULT_REGION=us-west-1 aws --endpoint-url=http://localhost:4566 s3api create-bucket --bucket test-bucket --create-bucket-configuration LocationConstraint=us-west-1
{
    "Location": "http://test-bucket.s3.localhost.localstack.cloud:4566/"
}

at 09:32:13 ➜ aws --endpoint-url=http://localhost:4566 s3api put-object --bucket test-bucket --key file.json --body README.md --checksum-algorithm SHA256
{
    "ETag": "\"4bb2f1387449d690bff6336ea255909c\"",
    "ChecksumSHA256": "bzOikXXMUqRTCrpVq7Pt7LjJ0fjR3ccUfM19S/gnfqA="
}

# SHA256 missing here
at 09:32:20 ➜ aws --endpoint-url=http://localhost:4566 s3api head-object --bucket test-bucket --key file.json --checksum-mode Enabled
{
    "AcceptRanges": "bytes",
    "LastModified": "2023-07-11T13:32:15+00:00",
    "ContentLength": 1455,
    "ETag": "\"4bb2f1387449d690bff6336ea255909c\"",
    "ContentType": "binary/octet-stream",
    "Metadata": {}
}
```

Note the equivalent response from S3 actual includes the SHA256 value

```shell
at 10:21:23 ➜ aws s3api head-object --bucket test-bucket --key file.json --checksum-mode Enabled
{
    "AcceptRanges": "bytes",
    "Expiration": "expiry-date=\"Thu, 13 Jul 2023 00:00:00 GMT\", rule-id=\"all\"",
    "LastModified": "2023-07-11T14:21:09+00:00",
    "ContentLength": 1956,
    "ChecksumSHA256": "bj7fqCqtaF95M1ULwQRDJuHbL/Xd9NVMH6pua9OINcc=",
    "ETag": "\"f4be535d45019a4408dd5369986919f8\"",
    "ContentEncoding": "",
    "ContentType": "binary/octet-stream",
   
    "Metadata": {},
    
}
```

_Originally posted by @bdurrani in https://github.com/localstack/localstack/issues/6659#issuecomment-1630932643_
            
key_object.set_expiry(expires)
        elif "expires" in key_object.metadata:  
            metadata = {k: v for k, v in key_object.metadata.items() if k != "expires"}
            key_object.set_metadata(metadata, replace=True)
        if key_object.kms_key_id:
            
            key_object.kms_key_id = arns.kms_key_arn(
                key_id=key_object.kms_key_id,
                account_id=moto_bucket.account_id,
                region_name=moto_bucket.region_name,
            )
            response["SSEKMSKeyId"] = key_object.kms_key_id
        if key_object.checksum_algorithm == ChecksumAlgorithm.CRC32C:
            
            
            key_object.checksum_value = get_object_checksum_for_algorithm(
                ChecksumAlgorithm.CRC32C,
                key_object.value,
            )
        bucket_lifecycle_configurations = self.get_store(context).bucket_lifecycle_configuration
        if (bucket_lifecycle_config := bucket_lifecycle_configurations.get(request["Bucket"])) and (
            rules := bucket_lifecycle_config.get("Rules")
        ):
            object_tags = moto_backend.tagger.get_tag_dict_for_resource(key_object.arn)
            if expiration_header := self._get_expiration_header(rules, key_object, object_tags):
                response["Expiration"] = expiration_header
        self._notify(context)
        return response
    @handler("CopyObject", expand=False)
    def copy_object(