TST: test_to_csv_compression_encoding_gcs fails sometimes

[twoertwein]

only seems to happen sometimes in "Database / Linux_py37_cov"

_______________ test_to_csv_compression_encoding_gcs[zip-cp1251] _______________
[gw1] linux -- Python 3.7.9 /usr/share/miniconda/envs/pandas-dev/bin/python

gcs_buffer = <_io.BytesIO object at 0x7f4959d0b650>, compression_only = 'zip'
encoding = 'cp1251'

    @td.skip_if_no("gcsfs")
    @pytest.mark.parametrize("encoding", ["utf-8", "cp1251"])
    def test_to_csv_compression_encoding_gcs(gcs_buffer, compression_only, encoding):
        """
        Compression and encoding should with GCS.
    
        GH 35677 (to_csv, compression), GH 26124 (to_csv, encoding), and
        GH 32392 (read_csv, encoding)
        """
        from fsspec import registry
    
        registry.target.clear()  # remove state
        df = tm.makeDataFrame()
    
        # reference of compressed and encoded file
        compression = {"method": compression_only}
        if compression_only == "gzip":
            compression["mtime"] = 1  # be reproducible
        buffer = BytesIO()
        df.to_csv(buffer, compression=compression, encoding=encoding, mode="wb")
    
        # write compressed file with explicit compression
        path_gcs = "gs://test/test.csv"
        df.to_csv(path_gcs, compression=compression, encoding=encoding)
>       assert gcs_buffer.getvalue() == buffer.getvalue()
E       AssertionError: assert b'PK\x03\x04\...0\x00\x00\x00' == b'PK\x03\x04\...0\x00\x00\x00'
E         At index 10 diff: b'\xa6' != b'\xa5'
E         Use -v to get the full diff