Update iOS SDK to 5.5.0

Author: github-actions[bot]

plugin.xml

@@ -74,7 +74,7 @@
             <source url="https://cdn.cocoapods.org/"/>
         </config>
         <pods use-frameworks="true">
-            <pod name="OneSignalXCFramework" spec="5.4.2" />
+            <pod name="OneSignalXCFramework" spec="5.5.0" />
         </pods>
     </podspec>