Cannot inherit from class alias

Nobody has claimed this yet.

### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Annotations

### Expected Behaviour

If I have an `@alias` for a class, I expect it to be usable in inheritance for other classes, ex. `@class MyNewClass : MyAlias`

### Actual Behaviour

The inheritance triggers `undefined-doc-class` diagnostic although the alias can still be ctrl+clicked to go to its source.

### Reproduction steps

Snippet that reproduces the issue:
```lua
---@class MyClass

---@alias MyAlias MyClass

-- Will trigger undefined-doc-class, though MyAlias can be ctrl+clicked to go to source.
---@class MyNewClass : MyAlias

```

### Additional Notes

_No response_

### Log File

[service.log](https://github.com/LuaLS/lua-language-server/files/15048879/service.log)

Start with the supplied Lua reproduction and trace how @alias resolution is handled when a class declares inheritance. Done means MyNewClass : MyAlias no longer emits undefined-doc-class while the alias remains navigable to its source.

Written by the indexing model from the issue text.