Upgrade SDK bindings to v26.09.26 (#7780)

* Bump SDK bindings to `v26.09.26`

This version contains a fix for issues in `v26.09.25` related to certificate verification.

* Fix breaking API changes in the latest bindings

* Unify `FeatureFlags.RoomThreadList` with `FeatureFlags.Threads`

libraries/featureflag/api/src/main/kotlin/io/element/android/libraries/featureflag/api/FeatureFlags.kt

@@ -116,13 +116,6 @@ enum class FeatureFlags(
         defaultValue = { false },
         isFinished = false,
     ),
-    RoomThreadList(
-        key = "feature.room_thread_list",
-        title = "Add a list of threads in a room",
-        description = "Add a new screen with a list of threads in a room.",
-        defaultValue = { false },
-        isFinished = false,
-    ),
     AutomaticBackPagination(
         key = "feature.automatic_back_pagination",
         title = "Automatic back pagination of rooms",