Update SpigotAPI to 1.19.

This time around we're trying to keep the API version bumped for the
sake of not leaving the people who actually keep their servers updated
behind. It does present some potential backwards compatibility issues
when we do employ new API, but we'll just have to be mindful of _how_ we
go about doing so...

changelog.md

@@ -23,7 +23,7 @@ These changes will (most likely) be included in the next version.
 - (API) MobArena now fires MobArenaPreReloadEvent and MobArenaReloadEvent before and after, respectively, reloading its config-file. This should allow extensions and other plugins to better respond to configuration changes.
 
 ### Changed
-- MobArena now targets the Minecraft 1.17 version of the Spigot API (but still works on 1.13-1.16). This should make it easier to tackle feature requests and bug reports related to modern Minecraft.
+- MobArena now targets the Minecraft 1.19 version of the Spigot API (but still works on 1.13-1.18). This should make it easier to tackle feature requests and bug reports related to modern Minecraft.
 - Monsters are no longer stripped of the _weapons_ they spawn with naturally, only their _armor_. This should improve forwards compatibility with new weapon-reliant monsters.
 - The regex pattern for the player list command is now less greedy, so it will only match on `/ma players`, `/ma playerlist`, and `/ma player-list`. The previous pattern matched on anything that starts with `player`, which rendered the `/ma player-stats` command in MobArenaStats impossible to invoke.
 

pom.xml

@@ -89,7 +89,7 @@
     <dependency>
       <groupId>org.spigotmc</groupId>
       <artifactId>spigot-api</artifactId>
-      <version>1.17-R0.1-SNAPSHOT</version>
+      <version>1.19-R0.1-SNAPSHOT</version>
       <scope>provided</scope>
     </dependency>