chore(deps): update Cocoa SDK to v8.21.0 (#1909)

* chore: update flutter/scripts/update-cocoa.sh to 8.21.0

* Test auto commit

* Format

* Update

* Update main.dart

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Co-authored-by: GitHub <noreply@github.com>
Co-authored-by: GIancarlo Buenaflor <giancarlo_buenaflor@yahoo.com>

flutter/ios/sentry_flutter.podspec

@@ -12,7 +12,7 @@ Sentry SDK for Flutter with support to native through sentry-cocoa.
                          :tag => s.version.to_s }
   s.source_files     = 'Classes/**/*'
   s.public_header_files = 'Classes/**/*.h'
-  s.dependency 'Sentry/HybridSDK', '8.20.0'
+  s.dependency 'Sentry/HybridSDK', '8.21.0'
   s.ios.dependency 'Flutter'
   s.osx.dependency 'FlutterMacOS'
   s.ios.deployment_target = '11.0'