fix plugin build with ios simulator

example/ios/Flutter/AppFrameworkInfo.plist

@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>8.0</string>
+  <string>9.0</string>
 </dict>
 </plist>

example/pubspec.yaml

@@ -4,6 +4,7 @@ description: Demonstrates how to use the flutter_openim_sdk plugin.
 # The following line prevents the package from being accidentally published to
 # pub.dev using `pub publish`. This is preferred for private packages.
 #publish_to: 'none' # Remove this line if you wish to publish to pub.dev
+version: 1.0.0
 
 environment:
   sdk: ">=2.12.0 <3.0.0"