Also limit the dates we look at to most recent 10 distinct dates only. Closes#9930
(cherry picked from commit 6663abebaf69241741d0702331857951834ba806)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestorer.kt
# app/src/main/java/eu/kanade/tachiyomi/data/library/LibraryUpdateJob.kt