build: мелкие правки в build.gradle

fluent.syntax/build.gradle

@@ -1,15 +1,14 @@
 plugins {
-    id "java"
-}
-
-compileJava {
-    targetCompatibility = sourceCompatibility = JavaVersion.VERSION_17
-    options.encoding = "UTF-8"
+    id("java")
 }
 
 group = "ru.di9.fluent"
 version = "1.0-SNAPSHOT"
 
+java.toolchain {
+    languageVersion = JavaLanguageVersion.of(17)
+}
+
 repositories {
     mavenLocal()
     mavenCentral()
@@ -42,4 +41,3 @@ dependencies {
 test {
     useJUnitPlatform()
 }
-