Fix exporting of Docker image layers

The logic to extract layers from a downloaded Docker image assumed that
the layer entries in the image tar archive always had the file extension
`.tar`. This was the case with Docker and other compatible daemons until
Docker 25.0. With this commit, the extension is no longer assumed, but
any entries listed in `manifest.json` will be recognized.

Fixes gh-39323

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/ImageBuildpackTests.java

@@ -21,6 +21,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
@@ -189,6 +190,7 @@ class ImageBuildpackTests extends AbstractJsonTests {
 				tarOut.finish();
 			}
 			consumer.accept("test", tarFile.toPath());
+			Files.delete(tarFile.toPath());
 		}
 		catch (IOException ex) {
 			fail("Error writing mock layers", ex);

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/DockerApiTests.java

@@ -382,6 +382,7 @@ class DockerApiTests {
 		}
 
 		@Test
+		@SuppressWarnings("removal")
 		void exportLayerFilesDeletesTempFiles() throws Exception {
 			ImageReference reference = ImageReference.of("gcr.io/paketo-buildpacks/builder:base");
 			URI exportUri = new URI(IMAGES_URL + "/gcr.io/paketo-buildpacks/builder:base/get");