Interoperability of ed25519 keys

Nobody has claimed this yet.

### Summary

I have not much experience in p2p networking or ed25519, but I think I'm experiencing interoperability issues between py-libp2p and some rust p2p code based on curve25519-dalek. What I'm seeing is that py-libp2p will happily create a keypair, of which the public key is already rejected by curve25519-dalek on object instantiation.

Specifically, the keys sometimes fail [the test done by curve25519-dalek](https://github.com/dalek-cryptography/curve25519-dalek/blob/adb6a12b4a617659808c5c4de3ecb69d79d373a4/curve25519-dalek/src/edwards.rs#L234), apparently because they are 'not on the/a curve'.

Maybe this relates to [ZIP-0215](https://zips.z.cash/zip-0215) criteria. Interoperability issues seem to be [present for years](https://hdevalence.ca/blog/2020-10-04-its-25519am/).

I hacked together a validation test on the python end (mimicking the rust code), which does `seed[0]++` in a loop until [the generated key](https://github.com/libp2p/py-libp2p/blob/74f4aaf136a022b5a8786bd7e57974b8f6033e7f/libp2p/crypto/ed25519.py#L57) passes the test. This solves the issue.

But again, no experience or knowledge, so I might be missing something here, any feedback is welcome.

### Expected behavior

I expect py-libp2p to be able to inter-operate with other libp2p implementations and not generate keys that other implementations reject as invalid.

### Actual behavior

py-libp2p generates keypairs of which the public key cannot be loaded by rust code based on curve25519-dalek.

### Relevant log output

```shell

```

### Possible Solution

Implement key validation as part of generating random keypairs.

### Environment

```shell

```

### Would you like to work on fixing this bug ?

Yes

Start in libp2p/crypto/ed25519.py around line 57 and compare its generated public keys with the validation referenced in curve25519-dalek and ZIP-0215. Reproduce the reported rejection and determine the interoperability criteria; done means generated py-libp2p keys are accepted by the referenced Rust implementation without relying on ad hoc seed changes.

Written by the indexing model from the issue text.