## Description

This removes all of the comments that are of the form "so-and-so (must not be null|can ?not be null|must be non-null)" from the cases where those values are defines as non-nullable values.

This PR removes them from the material library.

This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.

In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.

This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases.  I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).

## Related PRs
- https://github.com/flutter/flutter/pull/134984
- https://github.com/flutter/flutter/pull/134992
- https://github.com/flutter/flutter/pull/134993
- https://github.com/flutter/flutter/pull/134994

## Tests
 - Documentation only change.

It's time to say good bye to an old friend. 
It has outlived its usefulness.
Farewell, AbstractNode! 🫡

Remove 1745 decorative breaks

`OverlayPortal` 

* dart fix --apply

* manual fixes

* Added support for surfaceTintColor and shadowColor to the Dialog widgets.
* Updated the defaults for Material.shadowColor and Material.surfaceTint to allow turning off the features with a transparent color.
* Added support for shadowColor and surfaceTintColor for Drawer widget.

* Improve `useMaterial3` documentation

* reverse styles and components

* tweak language around support

* Update theme_data.dart

* remove trailing space

* Update packages/flutter/lib/src/material/theme_data.dart
Co-authored-by: Darren Austin <darren@darrenaustin.org>

* add missing spec links

* remove spec links from useMaterial3

* move defaults section up, rejig things

* spaces no longer trailing

* spaces no longer trailing (2)
Co-authored-by: Darren Austin <darren@darrenaustin.org>

* Use `curly_braces_in_flow_control_structures` for `material`

* include test/material

* add back removed comments

This reverts commit 5fd259be.

This reverts commit 437ff210.

Revert "Let InkWell/Ink/ancestor support GlobalKey so that splash does not stop when changing position. (#71138)" (#79300)

This reverts commit e7266dbb.

Let InkWell/Ink/ancestor support GlobalKey so that splash does not stop when changing position. (#71138)