Fixup for failing Beta CI (#2092)

Turns out, we shipped a new Flutter beta as well. 

Commenting out `experimental/varfont_shader_puzzle` from beta CI

Everything else is just cleanup.

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel
channel on [Discord].

<!-- Links -->
[Flutter Style Guide]:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo
[CLA]: https://cla.developers.google.com/
[Discord]: https://github.com/flutter/flutter/wiki/Chat
[Contributors Guide]:
https://github.com/flutter/samples/blob/main/CONTRIBUTING.md

add_to_app/android_view/flutter_module_using_plugin/pubspec.yaml

@@ -4,7 +4,7 @@ description: An example Flutter module that uses a plugin.
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter:

add_to_app/books/flutter_module_books/pubspec.yaml

@@ -6,7 +6,7 @@ description: A Flutter module using the Pigeon package to demonstrate
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter:

add_to_app/fullscreen/flutter_module/pubspec.yaml

@@ -4,7 +4,7 @@ description: An example Flutter module.
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter:

add_to_app/multiple_flutters/multiple_flutters_module/pubspec.yaml

@@ -4,7 +4,7 @@ description: A module that is embedded in the multiple_flutters_ios and multiple
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter:

add_to_app/plugin/flutter_module_using_plugin/pubspec.yaml

@@ -4,7 +4,7 @@ description: An example Flutter module that uses a plugin.
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter:

add_to_app/prebuilt_module/flutter_module/pubspec.yaml

@@ -4,7 +4,7 @@ description: An example Flutter module.
 version: 1.0.0+1
 
 environment:
-  sdk: '>=2.19.5 <4.0.0'
+  sdk: ^3.2.0
 
 dependencies:
   flutter: