Include flutter_runner in precache artifacts. (#36318)

diff --git a/packages/flutter_tools/test/general.shard/cache_test.dart b/packages/flutter_tools/test/general.shard/cache_test.dart
index e2fe07e..07c5c18 100644
--- a/packages/flutter_tools/test/general.shard/cache_test.dart
+++ b/packages/flutter_tools/test/general.shard/cache_test.dart
@@ -169,6 +169,15 @@
     FileSystem: () => MockFileSystem(),
   });
 
+  test('Unstable artifacts', () {
+    expect(DevelopmentArtifact.web.unstable, true);
+    expect(DevelopmentArtifact.linux.unstable, true);
+    expect(DevelopmentArtifact.macOS.unstable, true);
+    expect(DevelopmentArtifact.windows.unstable, true);
+    expect(DevelopmentArtifact.fuchsia.unstable, true);
+    expect(DevelopmentArtifact.flutterRunner.unstable, true);
+  });
+
   group('EngineCachedArtifact', () {
     FakeHttpClient fakeHttpClient;
     FakePlatform fakePlatform;