[various] Use RadioGroup for groupValue and onChanged

[Phantom-101]

Use RadioGroup to avoid deprecated groupValue and onChanged (flutter/flutter#170915)

Pre-Review Checklist

• [X] I read the Contributor Guide and followed the process outlined there for submitting PRs.
• [X] I read the Tree Hygiene page, which explains my responsibilities.
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• [X] The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• [X] I linked to at least one issue that this PR fixes in the description above.
• [X] I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under[^1].
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[flutter-dashboard[bot]]

It looks like this pull request may not have tests. Please make sure to add tests or get an explicit test exemption before merging.

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

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[stuartmorgan-g]

Thanks for the contribution! Marking as a draft for now since this will require min SDK updates, and that can't be done in the PR until the next stable has shipped.

[stuartmorgan-g]

It should be possible to update this to be landable now that 3.35 has shipped to stable.

[stuartmorgan-g]

From triage: @Phantom-101 Are you still planning on updating this PR to resolve the CI failures?

[Phantom-101]

Sorry for the delay, I am currently busy with some other work so it may be a while before I update this.

[Piinks]

Hey @Phantom-101 we came across this in triage. I really appreciate your work here, and totally understand your last comment about not being able to return to it right away. Since this has many merge conflicts now I am going to close it. Please do feel free to open a fresh PR if you decide to come back to this work. Thank you!