Regarding CA1063 "Implement IDisposable correctly"

[Error CA1063](https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca1063) indicates the IDisposable isn't implemented correctly, and needs to be virtual for unsealed types.

This doesn't appear to have been used in the old repo has blocked the porting of some controls. Where this has happened, we've suppressed the error for now, keeping the original code as-is. This needs clarification.

@michael-hawker Do we want this to stay enabled going forward?

Documentation seems to suggest that this should never be suppressed, but conversations with @Sergio0694 and other members of the community indicate that this isn't critical.

_Originally posted by @Arlodotexe in https://github.com/CommunityToolkit/Windows/issues/72#issuecomment-1565086190_

```[tasklist]
### Tasks
- [ ] https://github.com/CommunityToolkit/Windows/issues/84
- [ ] https://github.com/CommunityToolkit/Labs-Windows/issues/443
```