Upgrade aws-sdk-s3 dependency (in tests) (#1750)

Upgrade `aws-sdk-s3` dependency (used in tests) to
[v1.120.0](https://crates.io/crates/aws-sdk-s3/1.120.0).

Addresses
[RUSTSEC-2026-0002](https://rustsec.org/advisories/RUSTSEC-2026-0002.html).

### Does this change impact existing behavior?

No.

### Does this change need a changelog entry? Does it require a version
change?

No.

---

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license and I agree to the terms of
the [Developer Certificate of Origin
(DCO)](https://developercertificate.org/).

Signed-off-by: Alessandro Passaro <[email protected]>

Author: passaro