Wipe repositories more often (#42511)

Fixes an issue where repositories are unintentionally shared among tests (given that the repo contents is captured in a static variable on the test class, to allow "sharing" among nodes) and two tests randomly chose the same snapshot name, leading to a conflict.

Closes #42519

plugins/repository-gcs/src/test/java/org/elasticsearch/repositories/gcs/GoogleCloudStorageBlobStoreRepositoryTests.java

@@ -27,7 +27,7 @@ import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.repositories.Repository;
 import org.elasticsearch.repositories.blobstore.ESBlobStoreRepositoryIntegTestCase;
-import org.junit.AfterClass;
+import org.junit.After;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -67,8 +67,8 @@ public class GoogleCloudStorageBlobStoreRepositoryTests extends ESBlobStoreRepos
         assertThat(repository, instanceOf(GoogleCloudStorageRepository.class));
     }
 
-    @AfterClass
-    public static void wipeRepository() {
+    @After
+    public void wipeRepository() {
         blobs.clear();
     }
 

plugins/repository-s3/src/test/java/org/elasticsearch/repositories/s3/S3BlobStoreRepositoryTests.java

@@ -38,7 +38,7 @@ import org.elasticsearch.rest.RestResponse;
 import org.elasticsearch.rest.action.admin.cluster.RestGetRepositoriesAction;
 import org.elasticsearch.test.rest.FakeRestRequest;
 import org.elasticsearch.threadpool.ThreadPool;
-import org.junit.AfterClass;
+import org.junit.After;
 import org.junit.BeforeClass;
 
 import java.util.Collection;
@@ -78,8 +78,8 @@ public class S3BlobStoreRepositoryTests extends ESBlobStoreRepositoryIntegTestCa
         }
     }
 
-    @AfterClass
-    public static void wipeRepository() {
+    @After
+    public void wipeRepository() {
         blobs.clear();
     }