extmod/uasyncio: Add manifest.py for freezing uasyncio Py files.

extmod/uasyncio/manifest.py

@@ -0,0 +1,13 @@
+# This list of frozen files doesn't include task.py because that's provided by the C module.
+freeze(
+    "..",
+    (
+        "uasyncio/__init__.py",
+        "uasyncio/core.py",
+        "uasyncio/event.py",
+        "uasyncio/funcs.py",
+        "uasyncio/lock.py",
+        "uasyncio/stream.py",
+    ),
+    opt=3,
+)