Update SDK constraint everywhere

[elliette]

No description provided.

[annagrin]

LGTM!

[kevmoo]

Is this required? I thought everything was opted-in to v3 by default?

CC @mit-mit @devoncarew

[mit-mit]

No, this is not required, see the 'Backwards compatibility for null safe packages' section in dart-lang/sdk#49530

Given it's a no-op, I'd recommend not churning all our packages for it. I'd recommend changing the upper constraint to <4.0.0 when you get to the point when you are also changing the lower constraint to >=3.0.0.

[elliette]

No, this is not required, see the 'Backwards compatibility for null safe packages' section in dart-lang/sdk#49530

Given it's a no-op, I'd recommend not churning all our packages for it. I'd recommend changing the upper constraint to <4.0.0 when you get to the point when you are also changing the lower constraint to >=3.0.0.

Got it, thank you! Closing in favor of #1817 (still a WIP) to fix the tests that are failing at head.