LibVideo: Remove declarations for non-existent methods

Author: https://github.com/AtkinsSJ
Commit: 5cc4b37bf3
Pull-request: https://github.com/SerenityOS/serenity/pull/17203
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibVideo/PlaybackManager.h

@@ -102,7 +102,6 @@ public:
     static constexpr SeekMode DEFAULT_SEEK_MODE = SeekMode::Accurate;
 
     static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> from_file(Core::Object& event_handler, StringView file);
-    static DecoderErrorOr<NonnullOwnPtr<PlaybackManager>> from_data(Core::Object& event_handler, Span<u8> data);
 
     PlaybackManager(Core::Object& event_handler, NonnullOwnPtr<Demuxer>& demuxer, Track video_track, NonnullOwnPtr<VideoDecoder>&& decoder);
 
@@ -211,9 +210,6 @@ public:
     }
     virtual ~PlaybackStatusChangeEvent() = default;
 
-    PlaybackStatus status();
-    PlaybackStatus previous_status();
-
 private:
     PlaybackStatus m_status;
     PlaybackStatus m_previous_status;