Remove unreleased changes section from RELEASENOTES.md

RELEASENOTES.md

@@ -1,21 +1,5 @@
  Release notes
 
-### Unreleased changes
-
-*   Core library:
-    *   Add `ExoPlayer.isTunnelingEnabled` to check if tunneling is enabled for
-        the currently selected tracks
-        ([#2518](https://github.com/google/ExoPlayer/issues/2518)).
-    *   Use `SingleThreadExecutor` for releasing `AudioTrack` instances to avoid
-        OutOfMemory errors when releasing multiple players at the same time
-        ([#10057](https://github.com/google/ExoPlayer/issues/10057)).
-*   Metadata:
-    *   `MetadataRenderer` can now be configured to render metadata as soon as
-        they are available. Create an instance with
-        `MetadataRenderer(MetadataOutput, Looper, MetadataDecoderFactory,
-        boolean)` to specify whether the renderer will output metadata early or
-        in sync with the player position.
-
 ### 1.0.0-beta02 (2022-07-21)
 
 This release corresponds to the