GH-3570: Disable the generation of the Gradle metadata

Fixes spring-projects/spring-integration#3570

The module file with the Gradle metadata cannot be published on Maven
Central, which causes issues for some people using a repository manager such
as Artifactory. If it doesn't return a 404 HTTP status, the build fails
instead of ignoring the module.

**Cherry-pick to `5.4.x` & `5.3.x`**

publish-maven.gradle

@@ -1,6 +1,10 @@
 apply plugin: 'maven-publish'
 apply plugin: 'com.jfrog.artifactory'
 
+tasks.withType(GenerateModuleMetadata) {
+	enabled = false
+}
+
 publishing {
 	publications {
 		mavenJava(MavenPublication) {