Fix unicode decode bug on surrogate error mode (#5546)

* subtract with overflow to check for whether to use surrogate

* enable test_argparse for windows on ci

------

Signed-off-by: Ashwin Naren <arihant2math@gmail.com>

.github/workflows/ci.yaml

@@ -17,7 +17,6 @@ concurrency:
 env:
   CARGO_ARGS: --no-default-features --features stdlib,zlib,importlib,encodings,sqlite,ssl
   # Skip additional tests on Windows. They are checked on Linux and MacOS.
-  # test_argparse: UnicodeDecodeError
   # test_glob: many failing tests
   # test_io: many failing tests
   # test_os: many failing tests
@@ -26,7 +25,6 @@ env:
   # test_unicode: AttributeError: module '_winapi' has no attribute 'GetACP'
   # test_venv: couple of failing tests
   WINDOWS_SKIPS: >-
-    test_argparse
     test_glob
     test_io
     test_os