fix(ios): bump ios min deployment to ios10 - remnant from invertase#4471

Note that the breaking change was in invertase#4471 and was called out in release notes
This is just a remnant where the pod utilities will likely give you more notice about it

Author: mikehardy

RNFBApp.podspec

@@ -15,7 +15,7 @@ Pod::Spec.new do |s|
   s.authors             = "Invertase Limited"
   s.source              = { :git => "https://github.com/invertase/react-native-firebase.git", :tag => "v#{s.version}" }
   s.social_media_url    = 'http://twitter.com/invertaseio'
-  s.ios.deployment_target = "9.0"
+  s.ios.deployment_target = "10.0"
   s.source_files        = "ios/**/*.{h,m}"
 
   # React Native dependencies