Mark cargo-dinghy 0.7.0 as broken

As of 2024-04-10 01:52 UTC, this release only contains a x86_64 Linux binaries.

```
Error: platform list in base manifest for cargo-dinghy contains x86_64_macos, but latest release (0.7.0) doesn't contain it; consider marking 0.7.0 as broken by adding 'broken' field to base manifest
```

https://github.com/sonos/dinghy/actions/runs/8618768640/job/23621914742#step:4:257

tools/codegen/base/cargo-dinghy.json

@@ -2,6 +2,7 @@
   "repository": "https://github.com/sonos/dinghy",
   "tag_prefix": "",
   "rust_crate": "${package}",
+  "broken": ["0.7.0"],
   "asset_name": "${package}-${rust_target_os}-${version}.tgz",
   "bin": "${package}-${version}/${package}${exe}",
   "platform": {