Revert "Remove the workaround for Guava issue 6801"

This reverts commit 131829e.

Author: Goooler

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/GradleProvisioner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2025 DiffPlug
+ * Copyright 2016-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,6 +26,7 @@
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.artifacts.ConfigurationContainer;
 import org.gradle.api.artifacts.dsl.DependencyHandler;
+import org.gradle.api.attributes.Attribute;
 import org.gradle.api.attributes.Bundling;
 import org.gradle.api.attributes.Category;
 import org.gradle.api.initialization.dsl.ScriptHandler;
@@ -124,6 +125,9 @@ private static Provisioner forConfigurationContainer(Project project, Configurat
 				config.attributes(attr -> {
 					attr.attribute(Category.CATEGORY_ATTRIBUTE, project.getObjects().named(Category.class, Category.LIBRARY));
 					attr.attribute(Bundling.BUNDLING_ATTRIBUTE, project.getObjects().named(Bundling.class, Bundling.EXTERNAL));
+					// TODO: This is a copy-paste from org.gradle.api.attributes.java.TargetJvmEnvironment which is added in Gradle 7.0, remove this once we drop support for Gradle 6.x.
+					// Add this attribute for resolving Guava dependency, see https://github.com/google/guava/issues/6801.
+					attr.attribute(Attribute.of("org.gradle.jvm.environment", String.class), "standard-jvm");
 				});
 				return config.resolve();
 			} catch (Exception e) {

testlib/src/main/java/com/diffplug/spotless/TestProvisioner.java

@@ -31,6 +31,7 @@
 import org.gradle.api.artifacts.Dependency;
 import org.gradle.api.artifacts.ResolveException;
 import org.gradle.api.artifacts.dsl.RepositoryHandler;
+import org.gradle.api.attributes.Attribute;
 import org.gradle.api.attributes.Bundling;
 import org.gradle.api.attributes.Category;
 import org.gradle.testfixtures.ProjectBuilder;
@@ -73,6 +74,9 @@ private static Provisioner createWithRepositories(Consumer<RepositoryHandler> re
 			config.attributes(attr -> {
 				attr.attribute(Category.CATEGORY_ATTRIBUTE, project.getObjects().named(Category.class, Category.LIBRARY));
 				attr.attribute(Bundling.BUNDLING_ATTRIBUTE, project.getObjects().named(Bundling.class, Bundling.EXTERNAL));
+				// TODO: This is a copy-paste from org.gradle.api.attributes.java.TargetJvmEnvironment which is added in Gradle 7.0, remove this once we drop support for Gradle 6.x.
+				// Add this attribute for resolving Guava dependency, see https://github.com/google/guava/issues/6801.
+				attr.attribute(Attribute.of("org.gradle.jvm.environment", String.class), "standard-jvm");
 			});
 			try {
 				return config.resolve();