Use Java 17 toolchain

Closes gh-15

Author: rainboyan

build.gradle

@@ -86,10 +86,10 @@ dependencies {
 
 bootJar.enabled = false
 
-sourceCompatibility = 17
-targetCompatibility = 17
-
 java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(17)
+    }
     withJavadocJar()
     withSourcesJar()
 }