Fix Rust 1.83.0 "elided_named_lifetimes" warning.

[deven]

Compiling aws-config v1.5.12 (.../aws-config)
warning: elided lifetime has a name
--> .../aws-config/src/meta/credentials/chain.rs:117:72
|
117 | fn provide_credentials<'a>(&'a self) -> future::ProvideCredentials<'_>
| -- lifetime 'a declared here ^^ this elided lifetime gets resolved as 'a
|
= note: #[warn(elided_named_lifetimes)] on by default

warning: elided lifetime has a name
--> .../aws-config/src/meta/token.rs:108:60
|
108 | fn provide_token<'a>(&'a self) -> future::ProvideToken<'_>
| -- lifetime 'a declared here ^^ this elided lifetime gets resolved as 'a

warning: elided lifetime has a name
--> .../aws-config/src/sts/assume_role.rs:317:72
|
317 | fn provide_credentials<'a>(&'a self) -> future::ProvideCredentials<'_>
| -- lifetime 'a declared here ^^ this elided lifetime gets resolved as 'a

Motivation and Context

Description

Testing

Checklist

• For changes to the smithy-rs codegen or runtime crates, I have created a changelog entry Markdown file in the .changelog directory, specifying "client," "server," or both in the applies_to key.
• For changes to the AWS SDK, generated SDK code, or SDK runtime crates, I have created a changelog entry Markdown file in the .changelog directory, specifying "aws-sdk-rust" in the applies_to key.

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[landonxjames]

Canary: https://github.com/smithy-lang/smithy-rs/actions/runs/12529495043