test: use the Kind constant instead of the string literal (#10524)

* test: use the Kind constant instead of the string literal

test/types.go defines `const Kind = "kind"` and most of the suite compares
against it, but three sites still use the bare string. deletion.go is
inconsistent with itself: the BeforeEach skip uses Kind while the one in
runBackupDeletionTests uses "kind", and its skip message hardcodes the
provider name where the other formats it.

namespace-mapping.go dot-imports test/e2e/test rather than test, so the
constant was not in scope there. Import the test package by name, as
test/e2e/migration/migration.go already does alongside its framework
import, and reference test.Kind.

No behavioural change: the constant's value is the string being replaced.

Signed-off-by: krishhna24 <krishhnatupedev@gmail.com>

* Add changelog for #10524

Signed-off-by: krishhna24 <krishhnatupedev@gmail.com>

---------

Signed-off-by: krishhna24 <krishhnatupedev@gmail.com>

test/e2e/backups/deletion.go

@@ -88,8 +88,8 @@ func runBackupDeletionTests(client TestClient, veleroCfg VeleroConfig, backupLoc
 	nsCount := len(workloadNamespaceList)
 	workloadNamespaces := strings.Join(workloadNamespaceList[:], ",")
 
-	if useVolumeSnapshots && veleroCfg.CloudProvider == "kind" {
-		Skip("Volume snapshots not supported on kind")
+	if useVolumeSnapshots && veleroCfg.CloudProvider == Kind {
+		Skip(fmt.Sprintf("Volume snapshots not supported on %s", Kind))
 	}
 	oneHourTimeout, ctxCancel := context.WithTimeout(context.Background(), time.Minute*60)
 	defer ctxCancel()