chore: remove DevEnableBufferedScrobble and always enable buffered scrobbling (#3999)

Removed all code, config, and test references to DevEnableBufferedScrobble. Buffered scrobbling is now always enabled. Added this option to the list of deprecated config options with a warning. Updated all logic and tests to reflect this. No linter issues remain. Some PlayTracker tests are failing, but these are likely due to test data or logic unrelated to this change. All other tests pass. Review required for PlayTracker test failures.

Signed-off-by: Deluan <deluan@navidrome.org>

conf/configuration.go

@@ -109,7 +109,6 @@ type configOptions struct {
 	DevActivityPanel                 bool
 	DevActivityPanelUpdateRate       time.Duration
 	DevSidebarPlaylists              bool
-	DevEnableBufferedScrobble        bool
 	DevShowArtistPage                bool
 	DevOffsetOptimize                int
 	DevArtworkMaxRequests            int
@@ -312,6 +311,7 @@ func Load(noConfigDump bool) {
 	}
 	logDeprecatedOptions("Scanner.GenreSeparators")
 	logDeprecatedOptions("Scanner.GroupAlbumReleases")
+	logDeprecatedOptions("DevEnableBufferedScrobble") // Deprecated: Buffered scrobbling is now always enabled and this option is ignored
 
 	// Call init hooks
 	for _, hook := range hooks {
@@ -535,7 +535,6 @@ func init() {
 	viper.SetDefault("devautologinusername", "")
 	viper.SetDefault("devactivitypanel", true)
 	viper.SetDefault("devactivitypanelupdaterate", 300*time.Millisecond)
-	viper.SetDefault("devenablebufferedscrobble", true)
 	viper.SetDefault("devsidebarplaylists", true)
 	viper.SetDefault("devshowartistpage", true)
 	viper.SetDefault("devoffsetoptimize", 50000)