Fix 'use conditional expression' where it was causing a null-ref warning.

[CyrusNajmabadi]

Fixes #75200
Fixes #63441

[CyrusNajmabadi]

@JoeRobich ptal :)

[ToddGrun]

yield break;

Curious what the yield break provides here

[CyrusNajmabadi]

nothing whatsoever :D i started with that tehre originally as i TDDed the impl of this. and i never removed. can do so in followup :)

[ToddGrun]

if (test is not null && test.Field is null)

Is something like the following handled?

if (test?.Field is not null)
{
test.Field = string.Empty;
}
else
{
throw new InvalidOperationException();
}

[CyrusNajmabadi]

probably not. i can see about handling that in followup.