BUG: read_excel does not use pyxlsb for xlsb files when engine is None
From `pandas.tests.io.excel.test_excel_read_binary_via_read_excel` (currently only in #38571):

```
        if read_ext == ".xlsb" and engine == "pyxlsb":
            with pytest.raises(IOError, match="File contains no valid workbook part"):
                with open("test1" + read_ext, "rb") as f:
                    pd.read_excel(f)
```

This should instead determine that pyxlsb should be used when installed and no error should be raised.