Integrade gradle toolchain to manage java versions (#985)

* Autodetection of installed toolchains
* Autoprovisioning if toolchain/jdk is not found

Author: marko-radosavljevic

build.gradle

@@ -51,6 +51,13 @@ subprojects {
     if (!skipSonarlint) {
         apply plugin: "name.remal.sonarlint"
     }
+    
+    java {
+        toolchain {
+            // Nails the Java-Version of every Subproject
+            languageVersion = JavaLanguageVersion.of(21)
+        }
+    }
 
     // sonarlint configuration, not to be confused with sonarqube/sonarcloud.
     sonarLint {
@@ -61,17 +68,6 @@ subprojects {
         }
     }
 
-    def compileTasks = {
-        options.encoding = 'UTF-8'
-
-        // Nails the Java-Version of every Subproject
-        sourceCompatibility = JavaVersion.VERSION_21
-        targetCompatibility = JavaVersion.VERSION_21
-    }
-
-    compileJava(compileTasks)
-    compileTestJava(compileTasks)
-
     spotless {
         java {
             // Excludes build folder since it contains generated java classes.

settings.gradle

@@ -1,7 +1,10 @@
+plugins {
+    id 'org.gradle.toolchains.foojay-resolver-convention' version '0.7.0'
+}
+
 rootProject.name = 'TJ-Bot'
 
 include 'application'
 include 'database'
 include 'formatter'
 include 'utils'
-