chore(ci): remove paper running plugin, switch out for a direct download/configure script so it can be easily tested on spigot, forge and the proxies

spigot/build.gradle

@@ -1,6 +1,3 @@
-plugins {
-    id("xyz.jpenilla.run-paper") version "1.0.6"
-}
 
 // Check the root build.gradle under allprojects for common settings
 configurations {
@@ -29,13 +26,3 @@ jar {
         it.isDirectory() ? it : zipTree(it)
     }
 }
-
-tasks {
-    runServer {
-        // Configure the Minecraft version for our task.
-        // This is the only required configuration besides applying the plugin.
-        // Your plugin's jar (or shadowJar if present) will be used automatically.
-        minecraftVersion("1.18.2")
-    }
-}
-