Remove beta webtoon viewer split page

This had a bunch of issues around split pages not showing up properly so things
end up appearing to be missing while reading.
It'd be more worthwhile redoing the reader viewers than trying to get this to work
properly. It'd be better to just enable the split pages on download instead.

Closes #8433

(cherry picked from commit 94cba9324c872b1f0caa3f4d385266f190a9b114)

# Conflicts:
#	app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsReaderScreen.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderPreferences.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonPageHolder.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonViewer.kt
#	core/src/main/java/tachiyomi/core/util/system/ImageUtil.kt

app/src/main/java/eu/kanade/presentation/reader/settings/ReadingModePage.kt

@@ -16,7 +16,6 @@ import eu.kanade.tachiyomi.ui.reader.setting.ReaderPreferences
 import eu.kanade.tachiyomi.ui.reader.setting.ReaderSettingsScreenModel
 import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType
 import eu.kanade.tachiyomi.ui.reader.viewer.webtoon.WebtoonViewer
-import eu.kanade.tachiyomi.util.system.isReleaseBuildType
 import tachiyomi.presentation.core.components.CheckboxItem
 import tachiyomi.presentation.core.components.HeadingItem
 import tachiyomi.presentation.core.components.SettingsChipRow
@@ -241,13 +240,6 @@ private fun ColumnScope.WebtoonViewerSettings(screenModel: ReaderSettingsScreenM
         )
     }
 
-    if (!isReleaseBuildType) {
-        CheckboxItem(
-            label = stringResource(R.string.pref_long_strip_split),
-            pref = screenModel.preferences.longStripSplitWebtoon(),
-        )
-    }
-
     CheckboxItem(
         label = stringResource(R.string.pref_double_tap_zoom),
         pref = screenModel.preferences.webtoonDoubleTapZoomEnabled(),