fix: Update sdk constraints to >=3.0.0

[spydon]

Description

Update the SDK constraint to use >= 3.0.0

Checklist

• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• No, this PR is not a breaking change.

Related Issues

[luanpotter]

LGTM

[Gustl22]

@spydon was there a special reason to do this? I don't find any docs which propose to use constraints for dart sdk >=3.0.0. I mean every depending app needs the same constraints now, so I think it's kind of breaking (?).
Flutter still uses older constraints, I guess. Does it make sense to revert this?
https://github.com/flutter/packages/blob/4a5cc3e6947b2b9840d7d810fe310e00726803fb/packages/video_player/video_player/pubspec.yaml#L9

Edit: never mind, Flutter also uses v.3.0.0 as min dependency :)
flutter/flutter#122546
Does it make sense to bump flutter min version to 3.10.0 as well as dart sdk 3.0.0 only comes with that version?

[spydon]

@spydon was there a special reason to do this? I don't find any docs which propose to use constraints for dart sdk >=3.0.0. I mean every depending app needs the same constraints now, so I think it's kind of breaking (?).

If we don't do this we can't use the new language features. And indeed, it's a bit breaking, but the migration should be trivial in almost all cases.

Does it make sense to bump flutter min version to 3.10.0 as well as dart sdk 3.0.0 only comes with that version?

Yeah, that totally makes sense, I just forgot. 😅