Update dart_test.yaml

Author: brianquinlan

pkgs/io_file/dart_test.yaml

@@ -1,10 +1,6 @@
 concurrency: 1
 reporter: compact
 test-randomize-ordering-seed: random
-on_platform:
-  # TODO(brianquinlan): Remove retries when
-  # https://github.com/dart-lang/sdk/issues/38832 is fixed.
-  android || ios || linux || mac-os:
-    retry: 1
-  windows:
-    retry: 3
+# TODO(brianquinlan): Remove retries when
+# https://github.com/dart-lang/sdk/issues/38832 is fixed.
+retry: 1