Unnecessary cast added to the `default` arm in the `IDE0066` fixer

[RenderMichael]

Version Used:

Steps to Reproduce:

class Program
{
    public object M(int i, string j)
    {
        switch (i, j)
        {
            case (0, _):
                return true;

            case (_, null):
                return true;

            default:
                return false;
        }
    }
}

Diagnostic Id:

"IDE0066: Use 'switch' expression"

Expected Behavior:

class Program
{
    bool M(int i, string j)
    {
        return (i, j) switch
        {
            (0, _) => true,
            (_, null) => true,
            _ => false,
        };
    }
}

Actual Behavior:

class Program
{
    public object M(int i, string j)
    {
        return (i, j)
switch
        {
            (0, _) => true,
            (_, null) => true,
            _ => (object)false,
        };
    }
}

[RenderMichael]

Noticed this issue while working on #77081. The indentation of switch is fixed there, and this issue is about the (object)false cast.

Happy to pick this up too.

[CyrusNajmabadi]

Go for it :)