tests: Replace umodule with module everywhere.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

tests/micropython/heapalloc_traceback.py

@@ -1,10 +1,10 @@
 # test that we can generate a traceback without allocating
 
 import micropython
-import usys
+import sys
 
 try:
-    import uio
+    import io
 except ImportError:
     print("SKIP")
     raise SystemExit
@@ -32,8 +32,8 @@ def test():
 test()
 
 # print the exception that was raised
-buf = uio.StringIO()
-usys.print_exception(global_exc, buf)
+buf = io.StringIO()
+sys.print_exception(global_exc, buf)
 for l in buf.getvalue().split("\n"):
     # uPy on pyboard prints <stdin> as file, so remove filename.
     if l.startswith("  File "):