Description of Bug

[14:44:05 WARN]: [Quests] Global task for Quests v3.15.2-b216e2b generated an exception
java.util.ConcurrentModificationException: null
at java.base/java.util.HashMap$HashIterator.nextNode(HashMap.java:1605) ~[?:?]
at java.base/java.util.HashMap$ValueIterator.next(HashMap.java:1633) ~[?:?]
at Quests-3.15.2-b216e2b-1.21.8.jar/com.leonardobishop.quests.bukkit.questcompleter.BukkitQuestCompleter.checkExpiredQuests(BukkitQuestCompleter.java:43) ~[Quests-3.15.2-b216e2b-1.21.8.jar:?]
at Quests-3.15.2-b216e2b-1.21.8.jar/com.leonardobishop.quests.bukkit.questcompleter.BukkitQuestCompleter.processExpiredCheckQueue(BukkitQuestCompleter.java:74) ~[Quests-3.15.2-b216e2b-1.21.8.jar:?]
at Quests-3.15.2-b216e2b-1.21.8.jar/com.leonardobishop.quests.bukkit.questcompleter.BukkitQuestCompleter.run(BukkitQuestCompleter.java:36) ~[Quests-3.15.2-b216e2b-1.21.8.jar:?]
at Quests-3.15.2-b216e2b-1.21.8.jar/com.leonardobishop.quests.bukkit.scheduler.folia.FoliaServerScheduler.lambda$runTaskTimer$5(FoliaServerScheduler.java:80) ~[Quests-3.15.2-b216e2b-1.21.8.jar:?]
at io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler$GlobalScheduledTask.run(FoliaGlobalRegionScheduler.java:179) ~[paper-1.21.8.jar:?]
at io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler.tick(FoliaGlobalRegionScheduler.java:37) ~[paper-1.21.8.jar:?]
at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1665) ~[paper-1.21.8.jar:1.21.8-60-29c8822]
at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1531) ~[paper-1.21.8.jar:1.21.8-60-29c8822]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1253) ~[paper-1.21.8.jar:1.21.8-60-29c8822]
at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:310) ~[paper-1.21.8.jar:1.21.8-60-29c8822]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?]

Steps to Reproduce

Just completed a Quest.

Environment

• Minecraft version: 1.21.8
• Server software: Paper
• Quests version: Quests-3.15.2-b216e2b

Agreements

• I am running the latest version of Quests
• I am certain this issue is unique and a similar issue is not currently open
• I am using a version of Minecraft which is supported by Quests

Other

No response