This adjusts the size of the delete button so that it takes up just slightly less than half of the chip, so that legacy tests that tap on the center of the chip still hit the chip, and not the delete button.

A follow-on change for #90531

In the process of fixing #90044, I realized that it's also possible for hovered tooltips to show more than one at a time if the widgets are nested, so this PR is a fix that prevents more than one tooltip from showing at a time with hovered tooltips.

This adds a smoke test for every single API example. It also fixes 17 tests that had bugs in them, or were otherwise broken, and even fixes one actual bug in the framework, and one limitation in the framework.

The bug in the framework is that NetworkImage's _loadAsync method had await response.drain<List<int>>();, but if the response is null, it will throw a cryptic exception saying that Null can't be assigned to List<int>. The fix was just to use await response.drain<void>(); instead.

The limitation is that RelativePositionedTransition takes an Animation<Rect> rect parameter, and if you want to use a RectTween with it, the value emitted there is Rect?, and one of the examples was just casting from Animation<Rect> to Animation<Rect?>, which is invalid, so I modified RelativePositionedTransition to take a Rect? and just use Rect.zero if the rect is null.

520be3012 Roll Dart SDK from 1998f61b08f7 to f452a6585cbd (2 revisions) (flutter/engine#28906) (#90877)

8a71e0ee4 [camera] Fix IllegalStateException being thrown in Android implementation when switching activities. (flutter/plugins#4319) (#90857)

94e5cb8b2 Roll Dart SDK from 06093fe5921e to 1998f61b08f7 (1 revision) (flutter/engine#28899) (#90852)

80b5d2ed3 [ci] Temporary run publish task on Flutter stable channel. (flutter/plugins#4388) (#90836)

5ec61962d [in_app_purchase] Bump dependencies on json_serializable, build_runner (flutter/plugins#4386) (#90823)

1564d21ce Roll Dart SDK from 9e2228a0e880 to 0cddaa9859a5 (1 revision) (flutter/engine#28874) (#90770)