fix: resolve Gradle exclusiveContent restriction for Forge plugin

- Remove all exclusiveContent blocks from settings.gradle pluginManagement
- Add net.minecraftforge.gradle 5.2.5 to settings.gradle plugins
- Remove buildscript block from forge/build.gradle
- Fixes: 'When using exclusive repository content, you cannot add repositories to buildscript.repositories'

Author: Meeuyt

settings.gradle

@@ -2,28 +2,13 @@ pluginManagement {
     repositories {
         gradlePluginPortal()
         mavenCentral()
-        exclusiveContent {
-            forRepository {
-                maven {
-                    name = 'Fabric'
-                    url = uri('https://maven.fabricmc.net')
-                }
-            }
-            filter {
-                includeGroup('net.fabricmc')
-                includeGroup('fabric-loom')
-            }
+        maven {
+            name = 'Fabric'
+            url = uri('https://maven.fabricmc.net')
         }
-        exclusiveContent {
-            forRepository {
-                maven {
-                    name = 'Sponge'
-                    url = uri('https://repo.spongepowered.org/repository/maven-public')
-                }
-            }
-            filter {
-                includeGroupAndSubgroups("org.spongepowered")
-            }
+        maven {
+            name = 'Sponge'
+            url = uri('https://repo.spongepowered.org/repository/maven-public')
         }
         maven {
             name = 'Forge'
@@ -32,6 +17,7 @@ pluginManagement {
     }
     plugins {
         id "org.jetbrains.kotlin.kapt" version '2.2.0'
+        id "net.minecraftforge.gradle" version "5.2.5"
     }
 }