Replace java.time APIs with kotlin(x).(date)time (#3001)

* Replace java.time APIs with kotlin(x).(date)time

kotlinx-datetime explicitly says in its README that it does not cover
i18n, so we have to stick with using their toJavaX converters wherever
we localise dates and times.

Yes, some of these replacements are... questionable. But I wanted to
try and maximise the replacement for now.

* Bump kotlinx-datetime to 0.8.0

* More kotlin.time/kotlinx-datetime replacements

* Remove redundant init block & make attributes val

* Replace new use of java.time.Instant

presentation-widget/src/main/java/tachiyomi/presentation/widget/BaseUpdatesGridGlanceWidget.kt

@@ -34,6 +34,9 @@ import coil3.transform.RoundedCornersTransformation
 import eu.kanade.tachiyomi.core.security.SecurityPreferences
 import eu.kanade.tachiyomi.util.system.dpToPx
 import kotlinx.coroutines.flow.map
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.minus
 import tachiyomi.core.common.util.lang.withIOContext
 import tachiyomi.domain.manga.model.MangaCover
 import tachiyomi.domain.updates.interactor.GetUpdates
@@ -46,8 +49,8 @@ import tachiyomi.presentation.widget.util.appWidgetBackgroundRadius
 import tachiyomi.presentation.widget.util.calculateRowAndColumnCount
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
-import java.time.Instant
-import java.time.ZonedDateTime
+import kotlin.time.Clock
+import kotlin.time.Instant
 
 abstract class BaseUpdatesGridGlanceWidget(
     private val context: Context = Injekt.get<Application>(),
@@ -90,7 +93,7 @@ abstract class BaseUpdatesGridGlanceWidget(
 
             val flow = remember {
                 getUpdates
-                    .subscribe(false, DateLimit.toEpochMilli())
+                    .subscribe(false, DateLimit.toEpochMilliseconds())
                     .map { rawData ->
                         rawData.prepareData(rowCount, columnCount)
                     }
@@ -153,6 +156,6 @@ abstract class BaseUpdatesGridGlanceWidget(
 
     companion object {
         val DateLimit: Instant
-            get() = ZonedDateTime.now().minusMonths(3).toInstant()
+            get() = Clock.System.now().minus(3, DateTimeUnit.MONTH, TimeZone.currentSystemDefault())
     }
 }

presentation-widget/src/main/java/tachiyomi/presentation/widget/WidgetManager.kt

@@ -21,7 +21,7 @@ class WidgetManager(
 
     fun Context.init(scope: LifecycleCoroutineScope) {
         combine(
-            getUpdates.subscribe(read = false, after = BaseUpdatesGridGlanceWidget.DateLimit.toEpochMilli()),
+            getUpdates.subscribe(read = false, after = BaseUpdatesGridGlanceWidget.DateLimit.toEpochMilliseconds()),
             securityPreferences.useAuthenticator.changes(),
             transform = { a, b -> a to b },
         )