Add ability to disable `FloatingActionButton` scale and rotation animations using `FloatingActionButtonAnimator.noAnimation`

[TahaTesser]

fixes [Proposal] Allow disabling the scaling animation of the FloatingActionButton

Using default FloatingActionButton animations

Using FloatingActionButtonAnimator.noAnimation

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• [x] I listed at least one issue that this PR fixes in the description above.
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[TahaTesser]

@HansMuller Resolved conflict in scaffold.dart and updated the branch. This introduces FloatingActionButtonAnimator.noAnimation specifically to disable FAB entry and exit animations.