Upgrade to hocuspocus 2.15.2

https://github.com/ueberdosis/hocuspocus/releases/tag/v2.15.1

What's Changed

• Doc: add missing await in "Editing a document locally" example. by @blep in #888
• build(deps): bump actions/cache from 4.1.2 to 4.2.0 by @dependabot in #886
• build(deps-dev): bump rollup from 2.79.0 to 2.79.2 by @dependabot in #887
• fix(server): pass WebSocket instead of Connection to applyAwarenessUpdate by @RubaXa in #882
• Transformer: move @tiptap/core to peerDependencies by @trulex in #865
• Fix links in extension list by @notpushkin in #891
• fix(comments): fix error where deletedComments yArray does not exist by @bdbch in #884
• adjust server global active connection counter to consider multiplexing by @0xb4lamx in #890
• fix: prevent 'afterUnloadDocument' being triggered immediately after onLoadDocument by @bencarletonn in #893