fix: remove unmaintained pin-utils from AWS dependencies (#4874)

`cargo deny` rejects `pin-utils 0.1.0` as unmaintained under
RUSTSEC-2026-0441; there is no patched release. The dependency comes
from the AWS Smithy graph. Refresh that graph to include [smithy-rs
#4882](https://github.com/smithy-lang/smithy-rs/pull/4882), replacing
the obsolete `aws-smithy-types = ">=1.3.6, <1.7"` constraint with
`1.9.1`.

The lockfile audit attributes every changed package identity and
resolved dependency edge to the AWS graph. Existing git dependency pins
are preserved. The selected AWS crates declare Rust 1.94.1, within the
workspace's unchanged 1.95.0 requirement.

Validation at the exact candidate on the development EC2 host, both exit
0:

- `mbx +1.97.1 deny check advisories bans licenses sources`
- `mbx +1.97.1 check --quiet --locked -p lancedb --tests --features
remote,aws,dynamodb,bedrock`

The second command compiles the selected test targets; it is not a
runtime integration test. Full all-features compilation remains
unverified: an earlier attempt stopped in lance-linalg because the host
Clang 15 does not support the required `_Float16` target.

Cargo.toml

@@ -49,8 +49,7 @@ arrow-select = "59.2.0"
 arrow-cast = "59.2.0"
 arrow-flight = { version = "59.2.0", features = ["flight-sql-experimental"] }
 async-trait = "0"
-# Smithy JSON 0.63 requires the pre-1.7 Document representation; allow the MSRV pin.
-aws-smithy-types = ">=1.3.6, <1.7"
+aws-smithy-types = "1.9.1"
 base64 = "0.22"
 bytes = "1"
 datafusion = { version = "55.0.0", default-features = false }