Configure Gradle toolchain auto-provisioning

This commit configures the Foojay resolver plugin in the Gradle build in
order to auto-provision a required JDK distribution if it's not present
already on the host.

Currently the Spring Framework build requires both a JDK 17 and a JDK 21
distribution to build artifacts.

Closes gh-30474

Author: bclozel

buildSrc/src/main/java/org/springframework/build/JavaConventions.java

@@ -27,6 +27,8 @@
 import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.tasks.compile.JavaCompile;
 import org.gradle.jvm.toolchain.JavaLanguageVersion;
+import org.gradle.jvm.toolchain.JavaToolchainSpec;
+import org.gradle.jvm.toolchain.JvmVendorSpec;
 
 /**
  * {@link Plugin} that applies conventions for compiling Java sources in Spring Framework.
@@ -70,8 +72,10 @@ public void apply(Project project) {
 	 * @param project the current project
 	 */
 	private void applyJavaCompileConventions(Project project) {
-		project.getExtensions().getByType(JavaPluginExtension.class)
-				.getToolchain().getLanguageVersion().set(JavaLanguageVersion.of(17));
+		project.getExtensions().getByType(JavaPluginExtension.class).toolchain(toolchain -> {
+			toolchain.getVendor().set(JvmVendorSpec.BELLSOFT);
+			toolchain.getLanguageVersion().set(JavaLanguageVersion.of(17));
+		});
 		project.getTasks().withType(JavaCompile.class)
 				.matching(compileTask -> compileTask.getName().equals(JavaPlugin.COMPILE_JAVA_TASK_NAME))
 				.forEach(compileTask -> {

settings.gradle

@@ -1,6 +1,7 @@
 plugins {
 	id "com.gradle.enterprise" version "3.14"
 	id "io.spring.ge.conventions" version "0.0.13"
+	id "org.gradle.toolchains.foojay-resolver-convention" version "0.7.0"
 }
 
 include "spring-aop"