Replace the deprecated libolm with something more secure

[jtrees]

Some vulnerabilities in libolm have been disclosed, which in response has been deprecated by the Matrix developers in favour of vodozemac. Is migrating to vodozemac something that might be possible?

[tulir]

It'll probably be changed eventually as mentioned in https://mau.fi/blog/2024-08-mautrix-release/, fairly low priority though as there's nothing exploitable