v0.15.0

• Dev: added ValueTask<string?> GetAuthInfoAsync() in ICredentialProvider.
• Feat: Writer.DisposeAsync() waits for all in-flight messages to complete.
• Feat: Reader.DisposeAsync() waits for all pending commits to be completed.
• Breaking Change: IReader now implements IAsyncDisposable instead of IDisposable.
  This change requires updates to code that disposes IReader instances. Use await using instead of using.
• Breaking Change: IWriter now implements IAsyncDisposable instead of IDisposable.
  This change requires updates to code that disposes IWriter instances. Use await using instead of using.
• Topic Reader & Writer: update auth token in bidirectional stream.

Full Changelog: v0.14.1...v0.15.0