Element-R: Report events with withheld keys separately to Posthog. (#12755)

* Remove refs to deprecated method

`MatrixEvent.isEncryptedDisabledForUnverifiedDevices` is now deprecated

* Report new posthog code for withheld message keys

package.json

@@ -73,7 +73,7 @@
     },
     "dependencies": {
         "@babel/runtime": "^7.12.5",
-        "@matrix-org/analytics-events": "^0.23.0",
+        "@matrix-org/analytics-events": "^0.24.0",
         "@matrix-org/emojibase-bindings": "^1.1.2",
         "@matrix-org/matrix-wysiwyg": "2.37.4",
         "@matrix-org/react-sdk-module-api": "^2.4.0",