pin smithy-rs-tool-common with lockfile (#3942)

## Description
Seeing preview build failures across the board. Looks like `[email protected]`
was [released a few hours
ago](rust-lang/cargo#14939) and comes with a new
MSRV of 1.81. We don't have a lockfile for `smithy-rs-tool-common` for
some reason. This PR adds one.


```
~/sandbox/rs/smithy-rs/tools/ci-build/smithy-rs-tool-common on main ✗                                                                            [41d648d]  12:14
> cargo check
error: rustc 1.78.0 is not supported by the following package:
  [email protected] requires rustc 1.81
Either upgrade rustc or select compatible dependency versions with
`cargo update <name>@<current-ver> --precise <compatible-ver>`
where `<compatible-ver>` is the latest version supporting rustc 1.78.0
```

Added a lockfile and downgraded `home`:

```sh
> cargo update [email protected] --precise 0.5.9
```

## Testing
Build locally + CI.

## Questions 

Lockfiles do not appear to be updated automatically for anything under
`ci-build` unless I'm missing something. This is probably fine as our
use of lockfiles is intended to catch issues with consumers of
`smithy-rs` and the SDK not our own internal tooling.

----

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

Co-authored-by: Zelda Hessler <[email protected]>