RUSTSEC-2024-0370: proc-macro-error is unmaintained

> proc-macro-error is unmaintained

| Details | |
| ------------------- | ---------------------------------------------- |
| Status | unmaintained |
| Package | `proc-macro-error` |
| Version | `1.0.4` |
| URL | [https://gitlab.com/CreepySkeleton/proc-macro-error/-/issues/20](https://gitlab.com/CreepySkeleton/proc-macro-error/-/issues/20) |
| Date | 2024-09-01 |

proc-macro-error's maintainer seems to be unreachable, with no commits for 2 years, no releases pushed for 4 years, and no activity on the GitLab repo or response to email.

proc-macro-error also depends on `syn 1.x`, which may be bringing duplicate dependencies into dependant build trees.

## Possible Alternative(s)

- [manyhow](https://crates.io/crates/manyhow)
- [proc-macro-error2](https://crates.io/crates/proc-macro-error2)
- [proc-macro2-diagnostics](https://github.com/SergioBenitez/proc-macro2-diagnostics)

See [advisory page](https://rustsec.org/advisories/RUSTSEC-2024-0370.html) for additional details.

No files, tests, or entry points are named. Start by locating proc-macro-error in the repository's dependency manifests and inspecting the dependency tree; the issue does not specify which alternative to use or define acceptance criteria for completion.

Written by the indexing model from the issue text.