Bump Gradle to 9.8, update Shadow plugin to 9.2.2, Java toolchain to 25, and Cosmos API to 26.3.build.19-alpha

build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
     id("java")
-    id("com.github.johnrengelman.shadow") version "7.1.1"
+    id("com.gradleup.shadow") version "9.2.2"
     id("maven-publish")
 }
 
@@ -12,7 +12,7 @@ apply<JavaLibraryPlugin>()
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(21))
+        languageVersion.set(JavaLanguageVersion.of(25))
     }
 }
 
@@ -58,7 +58,7 @@ tasks {
 }
 
 dependencies {
-    compileOnly("com.alttd.cosmos:cosmos-api:1.21.8-R0.1-SNAPSHOT") {
+    compileOnly("com.alttd.cosmos:cosmos-api:26.3.build.19-alpha") {
         isChanging = true
     }
     compileOnly("com.github.milkbowl:VaultAPI:1.7") {