Brotli v1.1.0 tests fail with pypy3

(moved from https://github.com/google/brotli-wheels/issues/19)

I tried to update the submodule to brotli v1.1.0 in https://github.com/google/brotli-wheels/commit/c7db3350aaa7d0b90da6f0ec3bec0568cdad09be (https://github.com/google/brotli-wheels/issues/18), but encountered an issue with pypy. The wheels get built but then when the tests are run, we get these sort of errors:

```
test__test_compress_file_quality_11_lgwin_10_random_org_10k (tests.bro_test.TestBroCompress) ... RPython traceback:
File "pypy_module_cpyext_1.c", line 6714, in wrapper_second_level__star_2_51
File "implement.c", line 26795, in dispatcher_41
Fatal RPython error: AssertionError
```

e.g. see CI log https://github.com/google/brotli-wheels/actions/runs/6085235897/job/16508840821#step:5:944

I don't know how to fix that, so for the time being I will simply disable building wheels for pypy...
If anybody would like to help fix this, they'll be welcome to send a PR.

Also note that pypy users may benefit from using the alternative CFFI-based bindings from https://github.com/python-hyper/brotlicffi, whose API is mostly a drop-in replacement for our official brotli bindings.