Fix blastMiningDropProcessing attempting to create ItemStacks from Materials that don't have valid items. Ref:

com.destroystokyo.paper.exception.ServerEventException: Could not pass event EntityExplodeEvent to mcMMO v2.2.019
	at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:71)
	at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.callEvent(PaperPluginManagerImpl.java:131)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:628)
	at org.bukkit.craftbukkit.event.CraftEventFactory.callEntityExplodeEvent(CraftEventFactory.java:2122)
	at net.minecraft.world.level.Explosion.finalizeExplosion(Explosion.java:856)
	at net.minecraft.world.level.Level.explode(Level.java:1730)
	at net.minecraft.server.level.ServerLevel.explode(ServerLevel.java:1767)
	at net.minecraft.world.level.Level.explode(Level.java:1684)
	at net.minecraft.world.entity.item.PrimedTnt.explode(PrimedTnt.java:245)
	at net.minecraft.world.entity.item.PrimedTnt.tick(PrimedTnt.java:195)
	at net.minecraft.server.level.ServerLevel.tickNonPassenger(ServerLevel.java:1236)
	at net.minecraft.world.level.Level.guardEntityTick(Level.java:1632)
	at net.minecraft.server.level.ServerLevel.lambda$tick$5(ServerLevel.java:736)
	at net.minecraft.world.level.entity.EntityTickList.forEach(EntityTickList.java:39)
	at net.minecraft.server.level.ServerLevel.tick(ServerLevel.java:707)
	at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1798)
	at net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:477)
	at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1600)
	at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1307)
	at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:328)
	at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.IllegalArgumentException: FIRE isn't an item
	at com.google.common.base.Preconditions.checkArgument(Preconditions.java:143)
	at org.bukkit.inventory.ItemStack.of(ItemStack.java:58)
	at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:138)
	at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:117)
	at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:104)
	at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:87)
	at mcMMO.jar//com.gmail.nossr50.skills.mining.MiningManager.blastMiningDropProcessing(MiningManager.java:210)
	at mcMMO.jar//com.gmail.nossr50.listeners.EntityListener.onEnitityExplode(EntityListener.java:832)
	at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor381.execute(Unknown Source)
	at org.bukkit.plugin.EventExecutor$2.execute(EventExecutor.java:77)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70)
	at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:53)
	... 20 more

src/main/java/com/gmail/nossr50/skills/mining/MiningManager.java

@@ -204,7 +204,7 @@ public class MiningManager extends SkillManager {
             if (isDropIllegal(blockState.getType()))
                 continue;
 
-            if (Probability.ofPercent(50).evaluate()) {
+            if (blockState.getType().isItem() && Probability.ofPercent(50).evaluate()) {
                 ItemUtils.spawnItem(getPlayer(),
                         Misc.getBlockCenter(blockState),
                         new ItemStack(blockState.getType()),