fix: use openstack as hcp metadata provider name

Previously was using the default value which had the 'mitchellh.' prefix

Author: mogrogan

builder/openstack/artifact.go

@@ -65,6 +65,7 @@ func (a *Artifact) State(name string) any {
 			log.Printf("[DEBUG] error encountered when creating a registry image %v", err)
 			return nil
 		}
+		img.ProviderName = "openstack"
 		return img
 
 	}

builder/openstack/artifact_test.go

@@ -70,7 +70,7 @@ func TestArtifactState_StateData(t *testing.T) {
 func TestArtifactState_hcpPackerRegistryMetadata(t *testing.T) {
 	artifact := &Artifact{
 		ImageId:        "foo",
-		BuilderIdValue: "openstack",
+		BuilderIdValue: "mitchellh.openstack",
 		SourceImage:    "bar",
 		Region:         "mordor-7",
 	}