Disable NBT Gradle toolchain support by default

In order to allow Liberica NIK usage.

Closes gh-1381

Author: sdeleuze

spring-aot-gradle-plugin/src/main/java/org/springframework/aot/gradle/SpringAotGradlePlugin.java

@@ -97,6 +97,7 @@ public void apply(final Project project) {
 
 		project.getPlugins().withType(JavaPlugin.class, javaPlugin -> {
 			GraalVMExtension graal = project.getExtensions().findByType(GraalVMExtension.class);
+			graal.getToolchainDetection().set(false);
 
 			// Create the "springAot" DSL extension for user configuration
 			project.getExtensions().create(EXTENSION_NAME, SpringAotExtension.class, project.getObjects());

spring-native-docs/src/main/asciidoc/getting-started-native-build-tools.adoc

@@ -219,6 +219,7 @@ The following example adds a `native` profile that triggers the plugin during th
 // The GraalVM native build tools plugin is applied and configured automatically
 ----
 
+NOTE: When used with Spring AOT, Native Build Tools Gradle toolchain support is disabled by default in order to avoid current limitations related to identifying in a reliable way JDK with native capabilities. See https://github.com/gradle/gradle/issues/18896[this related Gradle issue].
 
 ===== Maven Repository