sdk: remove Error::InconsistentState as it was unused

Author: bnjbvr

crates/matrix-sdk/CHANGELOG.md

@@ -17,6 +17,8 @@ Breaking changes:
   - `AttachmentConfig::generate_thumbnail` takes a `ThumbnailFormat`.
 - The `HttpError::UnableToCloneRequest` error variant has been removed because it was never used or
   generated by the SDK.
+- The `Error::InconsistentState` error variant has been removed because it was never used or
+  generated by the SDK.
 
 Additions:
 

crates/matrix-sdk/src/error.rs

@@ -302,11 +302,6 @@ pub enum Error {
     #[error("wrong room state: {0}")]
     WrongRoomState(WrongRoomState),
 
-    /// The client is in inconsistent state. This happens when we set a room to
-    /// a specific type, but then cannot get it in this type.
-    #[error("The internal client state is inconsistent.")]
-    InconsistentState,
-
     /// Session callbacks have been set multiple times.
     #[error("session callbacks have been set multiple times")]
     MultipleSessionCallbacks,