refactor: changed flame dep to vector_math for vector2

packages/geometry/lib/src/geometry.dart

@@ -1,5 +1,6 @@
 import 'dart:math' as math;
-import 'package:flame/extensions.dart';
+
+import 'package:vector_math/vector_math.dart';
 
 /// Calculates all [Vector2]s of a circumference.
 ///

packages/geometry/pubspec.yaml

@@ -7,7 +7,7 @@ environment:
   sdk: ">=2.16.0 <3.0.0"
 
 dependencies: 
-  flame: ^1.0.0
+  vector_math: ^2.1.1
 
 dev_dependencies:
   mocktail: ^0.2.0

packages/geometry/test/src/geometry_test.dart

@@ -1,7 +1,8 @@
 // ignore_for_file: prefer_const_constructors, cascade_invocations
-import 'package:flame/extensions.dart';
+
 import 'package:geometry/geometry.dart';
 import 'package:test/test.dart';
+import 'package:vector_math/vector_math.dart';
 
 class Binomial {
   Binomial({required this.n, required this.k});