Fix code examples for doctests
This PR fixes some code examples to pass the doctests for the pipeline and `AutoClass` tutorials. 

I was unable to pass the audio code examples on my local machine because soundfile is not supported on M1 yet. I was able to run and reproduce the code snippets in Colab though so I think they should also pass on the CI.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thanks for the work.

Other than the `>>>` things, there are 2 failures when I ran it.

For audio pipeline:
```
Expected:
    [{'label': 'calm', 'score': 0.1315},
     {'label': 'neutral', 'score': 0.1307},
     {'label': 'sad', 'score': 0.1274},
     {'label': 'fearful', 'score': 0.1261},
     {'label': 'happy', 'score': 0.1242}]
Got:
    [{'score': 0.1315, 'label': 'calm'}, {'score': 0.1307, 'label': 'neutral'}, {'score': 0.1274, 'label': 'sad'}, {'score': 0.1261, 'label': 'fearful'}, {'score': 0.1242, 'label': 'happy'}]

```
(this is just a format issue I think)

For vision pipeline:
```
Expected:
    [{'score': 0.4403, 'label': 'lynx, catamount'}, {'score': 0.0343, 'label': 'cougar, puma, catamount, mountain lion, painter, panther, Felis concolor'}, {'score': 0.0321, 'label': 'snow leopard, ounce, Panthera uncia'}, {'score': 0.0235, 'label': 'Egyptian cat'}, {'score': 0.023, 'label': 'tiger cat'}]
Got:
    [{'score': 0.4335, 'label': 'lynx, catamount'}, {'score': 0.0348, 'label': 'cougar, puma, catamount, mountain lion, painter, panther, Felis concolor'}, {'score': 0.0324, 'label': 'snow leopard, ounce, Panthera uncia'}, {'score': 0.0239, 'label': 'Egyptian cat'}, {'score': 0.0229, 'label': 'tiger cat'}]
```
~~(This might be due to some random ops. I remembered I have similar situations before. I can take a look too.)~~
I get deterministic results, which is on Ubuntu 20.04. It's not very clear why the result is different than the previous one in the doc. I also get the same results on my local Windows machine. Maybe we could just update the values, cc @sgugger?

<|||||>I don't know why you ask me @ydshieh this is not my PR ;-) <|||||>> I don't know why you ask me @ydshieh this is not my PR ;-)

I know. Just to make sure you are also fine with my suggestion about `just update the values`. But I guess I should be more confident 😄 