feat: updated sdk constraints

Author: rithik-dev

example/pubspec.lock

@@ -143,7 +143,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "2.0.0"
+    version: "2.0.1+2"
   flutter:
     dependency: "direct main"
     description: flutter

pubspec.yaml

@@ -8,13 +8,14 @@ issue_tracker: https://github.com/rithik-dev/firebase_notifications_handler/issu
 topics: 
   - flutter
   - firebase
-  - widget
+  - messaging
   - notifications
   - push-notifications
 
 environment:
-  sdk: ">=2.17.0 <4.0.0"
-  flutter: ">=2.5.0"
+  # constraints from http, path_provider, firebase_messaging, flutter_local_notifications dependencies
+  sdk: ^3.3.0
+  flutter: '>=3.19.0'
 
 scripts:
   pre_publish: dart format .; flutter pub publish --dry-run