Remove background app update check

We already check in the foreground. If the app isn't being foregrounded at all, then there isn't much
point in checking for an update.

(cherry picked from commit 42954609b94e13d8fadbf1f3769e9f32fa9e8447)

# Conflicts:
#	app/build.gradle.kts
#	app/src/main/java/eu/kanade/tachiyomi/data/updater/AppUpdateJob.kt

app/src/main/java/exh/EXHMigrations.kt

@@ -5,6 +5,7 @@ package exh
 import android.content.Context
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
+import androidx.work.WorkManager
 import eu.kanade.domain.backup.service.BackupPreferences
 import eu.kanade.domain.base.BasePreferences
 import eu.kanade.domain.chapter.interactor.DeleteChapters
@@ -109,9 +110,6 @@ object EXHMigrations {
             if (oldVersion < BuildConfig.VERSION_CODE) {
                 lastVersionCode.set(BuildConfig.VERSION_CODE)
 
-                if (BuildConfig.INCLUDE_UPDATER) {
-                    AppUpdateJob.setupTask(context)
-                }
                 ExtensionUpdateJob.setupTask(context)
                 LibraryUpdateJob.setupTask(context)
                 BackupCreatorJob.setupTask(context)
@@ -518,6 +516,7 @@ object EXHMigrations {
                 if (oldVersion under 48) {
                     LibraryUpdateJob.cancelAllWorks(context)
                     LibraryUpdateJob.setupTask(context)
+                    WorkManager.getInstance(context).cancelAllWorkByTag("UpdateChecker")
                 }
 
                 // if (oldVersion under 1) { } (1 is current release version)