Fix library dependency issues (#3901)

## Motivation and Context
Smithy-rs CI and our release pipeline have exposed another place,
[sdk-adhoc-test](https://github.com/smithy-lang/smithy-rs/tree/main/aws/sdk-adhoc-test),
where we should place a Cargo lockfile but we currently don't.
Specifically, running `./gradlew aws:sdk-adhoc-test:check`on the current
main is encountering the following error:
```
error[E0658]: use of unstable library feature 'error_in_core'
  --> /opt/cargo/registry/src/index.crates.io-6f17d22bba15001f/idna-1.0.3/src/lib.rs:78:6
   |
78 | impl core::error::Error for Errors {}
   |      ^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #103765 <https://github.com/rust-lang/rust/issues/103765> for more information
```
We're supposed to pin `idna` to 0.5.0
([example](https://github.com/smithy-lang/smithy-rs/blob/62caa4639497bc9b18f57e51a30265899d9b511e/aws/sdk/Cargo.lock#L2812-L2819)),
but `sdk-adhoc-test` uses 1.0.3.

This PR will fix the problem by copying the checked-in SDK lockfile to
`sdk-adhoc-test`.

## Testing
- [x] `./gradlew aws:sdk-adhoc-test:check` from the repo root has passed
- [ ] Tests in CI

----

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