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

app/src/main/java/eu/kanade/domain/track/interactor/AddTracks.kt

@@ -8,6 +8,7 @@ import eu.kanade.tachiyomi.data.track.Tracker
 import eu.kanade.tachiyomi.data.track.TrackerManager
 import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.util.lang.convertEpochMillisZone
+import kotlinx.datetime.TimeZone
 import logcat.LogPriority
 import tachiyomi.core.common.util.lang.withIOContext
 import tachiyomi.core.common.util.lang.withNonCancellableContext
@@ -18,7 +19,6 @@ import tachiyomi.domain.manga.model.Manga
 import tachiyomi.domain.track.interactor.InsertTrack
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
-import java.time.ZoneOffset
 
 class AddTracks(
     private val insertTrack: InsertTrack,
@@ -62,8 +62,8 @@ class AddTracks(
 
                     firstReadChapterDate?.let {
                         val startDate = firstReadChapterDate.time.convertEpochMillisZone(
-                            ZoneOffset.systemDefault(),
-                            ZoneOffset.UTC,
+                            TimeZone.currentSystemDefault(),
+                            TimeZone.UTC,
                         )
                         track = track.copy(
                             startDate = startDate,