Deprecating constants for Media Player

As of Home Assistant Core 2022.5, the feature flag constants used in MediaPlayerEntity were deprecated and replaced by the MediaPlayerEntityFeature enum. Later, in 2022.10, the repeat mode, media type, and media class constants were deprecated and replaced by RepeatMode, MediaType, and MediaClass, respectively.

However, no proper deprecation was done, so now in 2024.10 we start the one-year deprecation period, and the constants will stop working from 2025.10, to ensure all custom integration authors have time to adjust.