chore: prepare for release 3.1.0 (#85)

* feat: add Android 15 support and update versions

- Update AGP version to 8.7.0
- Update gradle version to 8.10.2
- Update kotlin version to 2.1.0
- Update SDK version to 3.1.0 in README.md, package_info.dart, and pubspec.yaml

* feat: add Android 15 support and update dependencies

- Add Android 15 support
- Update AGP version to 8.7.0
- Update gradle version to 8.10.2
- Update kotlin version to 2.1.0

* Update date

Author: muzahidul-opti

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Optimizely Flutter SDK Changelog
 
+## 3.1.0
+October 9th, 2025
+
+This minor release added the following support:
+* Android 15 support ([#84](https://github.com/optimizely/optimizely-flutter-sdk/pull/84))
+* Update AGP version to 8.7.0
+* Update gradle version to 8.10.2
+* Update kotlin version to 2.1.0
+	
 ## 3.0.1
 Jun 4th, 2025
 

README.md

@@ -30,7 +30,7 @@ Other Flutter platforms are not currently supported by this SDK.
 To add the flutter-sdk to your project dependencies, include the following in your app's pubspec.yaml:
 
 ```
-   optimizely_flutter_sdk: ^3.0.1
+   optimizely_flutter_sdk: ^3.1.0
 ```
 
 Then run 

lib/package_info.dart

@@ -3,5 +3,5 @@
 
 class PackageInfo {
   static const String name = 'optimizely_flutter_sdk';
-  static const String version = '3.0.1';
+  static const String version = '3.1.0';
 }

pubspec.yaml

@@ -1,10 +1,10 @@
 name: optimizely_flutter_sdk
 description: This repository houses the Flutter SDK for use with Optimizely Feature Experimentation, Optimizely Full Stack (legacy), and Optimizely Rollouts.
-version: 3.0.1
+version: 3.1.0
 homepage: https://github.com/optimizely/optimizely-flutter-sdk
 
 environment:
-  sdk: '>=2.16.2 <4.0.0'
+  sdk: ">=2.16.2 <4.0.0"
   flutter: ">=2.5.0"
 
 dependencies: