Ignore RUSTSEC-2024-0370

```
error[unmaintained]: proc-macro-error is unmaintained
    ┌─ /home/runner/work/urdf-viz/urdf-viz/Cargo.lock:190:1
    │
190 │ proc-macro-error 1.0.4 registry+https://github.com/rust-lang/crates.io-index
    │ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ unmaintained advisory detected
    │
    ├ ID: RUSTSEC-2024-0370
    ├ Advisory: https://rustsec.org/advisories/RUSTSEC-2024-0370
    ├ 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)
    ├ Announcement: https://gitlab.com/CreepySkeleton/proc-macro-error/-/issues/20
    ├ Solution: No safe upgrade is available!
    ├ proc-macro-error v1.0.4
      └── structopt-derive v0.4.18
          └── structopt v0.3.26
              └── urdf-viz v0.45.2
                  └── urdf-viz-wasm v0.0.0
```

.deny.toml

@@ -11,6 +11,7 @@ ignore = [
     "RUSTSEC-2021-0139", # unmaintained (ansi_term), transitively dep of structopt (via old clap)
     "RUSTSEC-2021-0140", # unmaintained (rusttype), dep of kiss3d
     "RUSTSEC-2021-0150", # unmaintained (ncollide3d), dep of kiss3d
+    "RUSTSEC-2024-0370", # unmaintained (proc-macro-error), transitively dep of structopt
 ]
 
 # https://embarkstudios.github.io/cargo-deny/checks/bans/cfg.html