refactor(artifacts): Remove mutations of artifacts (#4638)

In an upcoming kork release, artifacts will become immutable to
prevent confusing bugs where (primarily in orca) we are mutating
copies of what we think we are mutating. There are a small number
of places in clouddriver where artifacts are mutated, but these
can be replaced by returning a copy with the desired changed.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

clouddriver-cloudfoundry/src/main/java/com/netflix/spinnaker/clouddriver/cloudfoundry/deploy/converters/DeployCloudFoundryServerGroupAtomicOperationConverter.java

@@ -95,8 +95,9 @@ private ArtifactCredentials getArtifactCredentials(
     String artifactAccount = artifact.getArtifactAccount();
     if (CloudFoundryArtifactCredentials.TYPE.equals(artifact.getType())) {
       CloudFoundryCredentials credentials = getCredentialsObject(artifactAccount);
-      artifact.setUuid(
-          getServerGroupId(artifact.getName(), artifact.getLocation(), credentials.getClient()));
+      String uuid =
+          getServerGroupId(artifact.getName(), artifact.getLocation(), credentials.getClient());
+      converted.setApplicationArtifact(artifact.toBuilder().uuid(uuid).build());
       return new CloudFoundryArtifactCredentials(credentials.getClient());
     }
 

clouddriver-ecs/src/main/java/com/netflix/spinnaker/clouddriver/ecs/deploy/ops/CreateServerGroupAtomicOperation.java

@@ -409,7 +409,11 @@ private File downloadTaskDefinitionArtifact(Artifact taskDefArtifact) {
         || taskDefArtifact.getArtifactAccount().isEmpty()
             && description.getTaskDefinitionArtifactAccount() != null
             && !description.getTaskDefinitionArtifactAccount().isEmpty()) {
-      taskDefArtifact.setArtifactAccount(description.getTaskDefinitionArtifactAccount());
+      taskDefArtifact =
+          taskDefArtifact
+              .toBuilder()
+              .artifactAccount(description.getTaskDefinitionArtifactAccount())
+              .build();
     }
     try {
       InputStream artifactInput = artifactDownloader.download(taskDefArtifact);

clouddriver-kubernetes/src/main/java/com/netflix/spinnaker/clouddriver/kubernetes/caching/agent/KubernetesCacheDataConverter.java

@@ -78,9 +78,6 @@ private static Optional<Keys.CacheKey> convertAsArtifact(
     try {
       KubernetesManifest lastAppliedConfiguration =
           KubernetesManifestAnnotater.getLastAppliedConfiguration(manifest);
-      if (artifact.getMetadata() == null) {
-        artifact.setMetadata(new HashMap<>());
-      }
       artifact.getMetadata().put("lastAppliedConfiguration", lastAppliedConfiguration);
       artifact.getMetadata().put("account", account);
     } catch (Exception e) {