Python runtime test failure with 4.10 and later

After upgrading the antlr4 python runtime past 4.9.1 (tested 4.10.1 and 4.11.1) in nixpkgs, we've been seeing its test suite fail with

```pytb
Traceback (most recent call last):
File "/build/source/runtime/Python3/tests/ctest.py", line 10, in
from parser.cparser import CParser
File "/build/source/runtime/Python3/tests/parser/cparser.py", line 631, in
class CParser ( Parser ):
File "/build/source/runtime/Python3/tests/parser/cparser.py", line 635, in CParser
atn = ATNDeserializer().deserialize(serializedATN())
File "/nix/store/ch8i929c63av55h9nxkinifh61mazf1h-python3.10-antlr4-python3-runtime-4.11.1/lib/python3.10/site-packages/antlr4/atn/ATNDeserializer.py", line 28, in deserialize
self.checkVersion()
File "/nix/store/ch8i929c63av55h9nxkinifh61mazf1h-python3.10-antlr4-python3-runtime-4.11.1/lib/python3.10/site-packages/antlr4/atn/ATNDeserializer.py", line 50, in checkVersion
raise Exception("Could not deserialize ATN with version " + str(version) + " (expected " + str(SERIALIZED_VERSION) + ").")
Exception: Could not deserialize ATN with version (expected 4).
```

The version returned seems to be `\x03`, while the test suite expects it to be `4`.

While similar to #3997 and #3895 we are running the test suite, not our own code.

We're running `python ctest.py` from the `tests` directory.

Start by running `python ctest.py` from `runtime/Python3/tests` and inspect the traceback through `tests/parser/cparser.py` into `antlr4/atn/ATNDeserializer.py`. Compare the serialized ATN version produced for the test parser with the runtime's expected version. Done means the Python runtime test suite passes for the affected 4.10 and later versions.

Written by the indexing model from the issue text.