Consider improving S3 creds mgmt

The following code is present on two different locations of the code:

```diff
- defaultCfg, err := config.LoadDefaultConfig(context.TODO())
+ defaultCfg, err := config.LoadDefaultConfig(
+ context.Background(),
+ )
```

The additions represent the change needed to support AWS CLI v2 properly (default in 2023?). Otherwise all `HeadObject` requests will fail with 400.

I'd open a PR, but seems like this project is abandoned by looking at the outstanding issues and PRs from external collaborators?

Search the codebase for the two occurrences of config.LoadDefaultConfig and inspect how they feed HeadObject requests. Apply the context change shown in the issue at both locations, then verify that HeadObject requests work with AWS CLI v2 credentials.

Written by the indexing model from the issue text.