### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### The Feature

Add a new `s3_callback_params` option (e.g. `s3_server_side_encryption_kms_key_id`) to the `s3_v2` logging integration (`litellm/integrations/s3_v2.py`) that, when set, adds the `x-amz-server-side-encryption-aws-kms-key-id` header to the signed `PUT` request — mirroring how `s3_server_side_encryption` (added for the algorithm, e.g. `"aws:kms"`) already works today.

Today, `s3_v2` can declare *that* an object should be encrypted with SSE-KMS (`aws:kms`), but has no way to declare *which* customer-managed KMS key ID/ARN to use on the request itself — only the bucket's own default-encryption configuration determines that:

```python # litellm/integrations/s3_v2.py, async_upload_data_to_s3 (also present in async_log_success_event's # sync counterpart, upload_data_to_s3) headers = { "Content-Type": "application/json", "Content-MD5": content_md5, "x-amz-content-sha256": content_hash, "Content-Language": "en", "Content-Disposition": f'inline; filename="{batch_logging_element.s3_object_download_filename}"', "Cache-Control": "priva…