Allow build 4.0.0 (#707)

## What does this change?

Allow `build 4.0.0`.

Fixes #706

## Type of change

Just allow users to use build 4.0.0 which will be required for other builders.

Author: BetterB0y

packages/runner/pubspec.yaml

@@ -11,7 +11,7 @@ environment:
 
 dependencies:
   flutter_gen_core: 5.11.0
-  build: '>=2.0.0 <4.0.0'
+  build: '>=2.0.0 <5.0.0'
   collection: ^1.17.0
   crypto: ^3.0.0
   glob: ^2.0.0