Inappropriate typo suggestion for argument of option

In --option=argument syntax, if the argument is not accepted by the option, then typo correction can suggest replacing the argument with a different option. That should not happen when they are connected by an equals sign.

## Demo

```XML

Exe
net6.0
enable
enable

```

```C#
using System.CommandLine;

return new RootCommand().Invoke(args);
```

```
$ dotnet run -- --version=h-
'h-' was not matched. Did you mean one of the following?
-h
1.0.0
```

Reproduce the behavior with the System.CommandLine sample using RootCommand and `dotnet run -- --version=h-`. Trace how the `--option=argument` form is parsed and how typo suggestions are generated; done means an invalid argument after `=` no longer suggests a different option while normal option suggestions still work.

Written by the indexing model from the issue text.