Create AppMigration09 to remove the cached well-known config from the SDK (#6026)

This value was most likely was incorrectly cached due to a previous issue in the SDK

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/MatrixClient.kt

@@ -214,7 +214,15 @@ interface MatrixClient {
      */
     fun createLinkDesktopHandler(): Result<LinkDesktopHandler>
 
+    /**
+     * Performs a database optimization that should flush cached data and improve performance.
+     */
     suspend fun performDatabaseVacuum(): Result<Unit>
+
+    /**
+     * Resets the cached client `well-known` config by the SDK.
+     */
+    suspend fun resetWellKnownConfig(): Result<Unit>
 }
 
 /**