Fix NF repositories

Apparently the root one was removed at some point, and now one must use
"/releases".

buildSrc/build.gradle.kts

@@ -14,13 +14,6 @@ repositories {
     mavenCentral()
     gradlePluginPortal()
 
-    maven("https://maven.neoforged.net") {
-        name = "NeoForge"
-        content {
-            includeGroup("net.neoforged")
-        }
-    }
-
     maven("https://maven.fabricmc.net/") {
         name = "Fabric"
         content {

projects/common/build.gradle.kts

@@ -23,8 +23,9 @@ configurations {
 }
 
 repositories {
-    maven("https://maven.neoforged.net/") {
-        content {
+    exclusiveContent {
+        forRepositories(maven("https://maven.neoforged.net/releases"))
+        filter {
             includeModule("org.spongepowered", "mixin")
         }
     }

settings.gradle.kts

@@ -8,13 +8,6 @@ pluginManagement {
         mavenCentral()
         gradlePluginPortal()
 
-        maven("https://maven.neoforged.net") {
-            name = "NeoForge"
-            content {
-                includeGroup("net.neoforged")
-            }
-        }
-
         maven("https://maven.fabricmc.net/") {
             name = "Fabric"
             content {