Use Gradle 8 compatible API

In Web3JGradle plugin replace an API that was removed in Gradle 8 with a
Gradle 8 API and an appropriate fallback.

Signed-off-by: Danno Ferrin <[email protected]>

build.gradle

@@ -36,6 +36,7 @@ apply {
 }
 
 repositories {
+    mavenLocal()
     maven {
         url 'https://plugins.gradle.org/m2/'
     }

gradle.properties

@@ -2,6 +2,6 @@ group=org.web3j
 version=4.11.2
 org.gradle.caching=true
 org.gradle.parallel=true
-solidityPluginVersion=0.4.0
+solidityPluginVersion=0.4.1-SNAPSHOT
 kotlinVersion=1.8.10
 junitVersion=4.12

src/main/java/org/web3j/gradle/plugin/Web3jPlugin.java

@@ -184,6 +184,11 @@ protected File buildOutputDir(final SourceSet sourceSet) {
         final SoliditySourceSet soliditySourceSet =
                 (SoliditySourceSet) convention.getPlugins().get(SoliditySourceSet.NAME);
 
-        return soliditySourceSet.getSolidity().getOutputDir();
+        try {
+            return soliditySourceSet.getSolidity().getDestinationDirectory().getAsFile().get();
+        } catch (NoSuchMethodError ignored) {
+            //TODO delete this catch block and unwrap the try block after Gradle 8 migration
+            return soliditySourceSet.getSolidity().getOutputDir();
+        }
     }
 }