sox.file_info.bitrate() Value error

When I call `sox.file_info.bitrate()` on a file I get the following error:

```
File "c:\Users\Theo\OneDrive\Documents\github\tinygrad\.venv\lib\site-packages\sox\file_info.py", line 64, in bitrate
return float(output[:-1])
ValueError: could not convert string to float: '256k'
```

Whilst when running `sox --i` on the same file in terminal I get the following:

```
Input File : 'dev-clean-wav/2277/149896/2277-149896-0000.wav'
Channels : 1
Sample Rate : 16000
Precision : 16-bit
Duration : 00:00:06.59 = 105440 samples ~ 494.25 CDDA sectors
File Size : 211k
Bit Rate : 256k
Sample Encoding: 16-bit Signed Integer PCM
```

After a bit of digging, it seems that the output of `soxi` is `256k\r` and the \r doesn't get stripped.

Start in file_info.py at the bitrate() entry point and reproduce the issue using the soxi output shown in the report, including its trailing carriage return. Done means the reported 256k bitrate is parsed successfully instead of raising ValueError, while existing bitrate behavior remains intact.

Written by the indexing model from the issue text.