Revert "Work around implicit usings breaking change (#7745)"

[RussKie]

This reverts commit 5f00dd2.

This broke Visual Basic, that requires implicit usings to work. dotnet/winforms#5437

To double check:

• The right tests are in and and the right validation has happened. Guidance: https://github.com/dotnet/core-eng/tree/master/Documentation/Validation

[riarenas]

I'm not sure we should do this. Afaiu, @tmat made this to unbreak a bunch of repos across the stack. Would it be possible to unblock winforms by enabling the feature in the failing projects?

[RussKie]

We absolutely have to do it. First it broke VB that "always" worked. And the implicit usings are being re-done in dotnet/sdk#19521 and dotnet/sdk#19599, and this property is no longer relevant...

[riarenas]

The sdk changes won't make it anywhere until we release one that includes them correct? I'd like to understand how this is a safe change for the other repos.

[RussKie]

dotnet/sdk#19599 was merged a week ago, it should have flown through to target repos.

[dreddy-work]

ping. All arcade updates into winforms repo are blocked. @tmat .

[mmitche]

@RussKie is it possible to conditionalize this on project type so that VB is supported, but C# keeps this behavior?

[RussKie]

@mmitche this property in Q was and is used only by VB targets. It was erroneously reused for C# scenarios in dotnet/sdk#18459, but reverted back in dotnet/sdk#19599. The whole implicit usings has been reimplemented.

IMO Arcade in general shouldn't be used for these kinds of changes. Each repo owner must opt-in or out of specific SDK features.

[mmitche]

Alright, I have no-concerns on reverting this.