Ensure reproducible builds and task avoidance when using x-content jar (#92212)

The elasticsearch-x-content jar is special in that it embeds other
runtime dependencies under an IMPL-JARS folder in the jar. This has
side-effects with Gradle runtime classpath normalization. This commit
fixes some isssues her by firstly, sorting the content of the jar
listing manifest so it's reproducible across filesystems, and secondly
ignoreing nested jar manifests for the purposes of runtime classpath
normalization, as they often contain things like timestamps and commit
hashes.

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchJavaBasePlugin.java

@@ -146,6 +146,7 @@ public class ElasticsearchJavaBasePlugin implements Plugin<Project> {
      */
     public static void configureInputNormalization(Project project) {
         project.getNormalization().getRuntimeClasspath().ignore("META-INF/MANIFEST.MF");
+        project.getNormalization().getRuntimeClasspath().ignore("IMPL-JARS/**/META-INF/MANIFEST.MF");
     }
 
     private static Provider<Integer> releaseVersionProviderFromCompileTask(Project project, AbstractCompile compileTask) {

libs/x-content/build.gradle

@@ -74,7 +74,7 @@ def generateProviderManifest = tasks.register("generateProviderManifest") {
   doLast {
     manifestFile.parentFile.mkdirs()
     manifestFile.setText(configurations.providerImpl.files.stream()
-      .map(f -> f.name).collect(Collectors.joining('\n')), 'UTF-8')
+      .map(f -> f.name).sorted().collect(Collectors.joining('\n')), 'UTF-8')
   }
 }