Remove `multidim-interop` action

With https://github.com/libp2p/test-plans/pull/308 merged, we now need to transition all implementation repositories to use the new action before we can remove the old one. I am opening this issue to track this effort.

```[tasklist]
- [ ] https://github.com/libp2p/rust-libp2p/issues/4592
- [ ] https://github.com/libp2p/go-libp2p/issues/2594
- [ ] https://github.com/status-im/nim-libp2p/issues/955
- [ ] https://github.com/MarcoPolo/zig-libp2p/issues/9
- [ ] https://github.com/libp2p/js-libp2p/issues/2128
```

Review the five linked implementation-repository issues first to verify that each repository has transitioned to the new action. Then inspect the old multidim-interop action in the test-plans repository and remove it only after all listed migrations are complete; done means the old action is gone and every task is resolved.

Written by the indexing model from the issue text.