Apply recommendation to sdk constraint

Author: simolus3

sqlite3/pubspec.yaml

@@ -5,7 +5,7 @@ homepage: https://github.com/simolus3/sqlite3.dart/tree/main/sqlite3
 issue_tracker: https://github.com/simolus3/sqlite3.dart/issues
 
 environment:
-  sdk: '>=2.18.0 <3.0.0'
+  sdk: '>=2.18.0 <4.0.0'
 
 dependencies:
   collection: ^1.15.0